Also, are we sure "لابس" is the word we want to teach as Standard Arabic? You'd say يلبس or يرتدي in Standard Arabic, wouldn't you? Is this a deliberate attempt to construct the sentence without a verb?
The makers of the course aren't trying to teach pure Standard Arabic here. They're trying to strike a balance between MSA and spoken language. As they mentioned in an article linked during the course launch:
we’re teaching a less-formal, spoken version of Modern Standard Arabic — not the version that would appear in poetry or formal news broadcasts, but instead the version that would be used once a newscaster stopped reading from their script and started talking to their interviewee. It’s a version of the language that can be used in a formal conversation, but one that also can be used with the widest range of Arabic speakers.
You can read their full article here https://making.duolingo.com/what-makes-arabic-hard-and-why-that-shouldnt-stop-you-from-learning-it
So would this be what they call "White Arabic?" I've heard this appellation used by Westerners and I've never been entirely clear on what it designated exactly.
I’ve never heard of such a term. No. This is just language we use every day. The Arab world is just as diverse as Europe is. Some expressions that are very common in one part of it might seem completely strange in another part. So I suggest not to take any one native speaker as a reference, and when asking if something is ‘wrong’, it’s better to specify by adding “is it wrong in MSA?” because a lot of natives might assume you’re asking about MSA when asking about right and wrong, but if MSA is all that matters, then every native Arab speaker speaks ‘wrong’ every day all day. That’s just silly. I think it’s best to approach language based on how people use it rather than try to impose some kind of artificial rules to it. Knowing the rules of MSA is good, but it would be wise to also be aware of its limitations and that it’s not the only ‘right’ way of speaking. It’s better to ask “is this MSA?” If it’s not MSA, it doesn’t mean that it’s ‘wrong’ or that some external culture is trying to impose itself on people, it just means that it’s correct as a dialect. It’s a different category.
I hate prescriptivism as much as you do, but no, this is not how we use the language everyday. This mishmash of standard and dialect is even more artificial than MSA. Some native speakers are complaining that words like شنطة aren't used in their dialect, so if the goal was to teach learners a register of Arabic that would be understood everywhere in the Arab world, حقيبة would have actually fared better for example. Anyway, from what I understand, White Arabic is supposed to be a mixture of dialects that is used by native speakers of different dialects when they communicate with each other, especially in the European diaspora. Many Arabic courses intended to teach Westerners "conversational" Arabic use it as a standard, rather than teach a specific dialect or MSA. But personally, when I speak with other Arabs, we each use our own dialect, and we end up understanding each other just fine for the most part. So I don't know if what we're speaking in that scenario would be classified as White Arabic.
I’m for teaching both شنطة and حقيبة. We use شنطة every day here (Lebanon). All I’m saying is that the course makers have an insurmountable goal in front of them, of somehow teaching multiple languages as one. I agree that the mishmash is artificial, but TV interviewers do it all the time because they’d rather be understood by most Arabs rather than speak pure MSA. Not all Arabs understand pure MSA. A lot of words are only known by specialists. Arabs understanding each other when they speak their own dialect is only anecdotal evidence. When people are friends, they get used to each other’s dialects, but millions of Arabs aren’t exposed to media outside their own local one or just to a few dialects with strong media presence such as Egyptian and Levantine Arabic. Given that Levantine Arabic is a lot closer to MSA than Egyptian Arabic, it would make sense for the course makers to choose Levantine Arabic when adding a few spoken terms and expressions here and there.
OK, then don't use MSA words only known by specialists, use MSA words known by everybody. And I wasn't talking about friends; strangers from all over the Arab world can make themselves understood when they want to, without using MSA. The dialects are like the Romance languages, they share features in common with each other than they don't with MSA. And anecdotal evidence is still evidence, it can't beat research, but it beats no evidence at all. But it actually isn't anecdotal evidence, because you can easily find research about the mutual intelligibility of the different Arabic dialects, and even Maltese. Also, I don't agree that Levantine Arabic is closer to MSA than Egyptian Arabic at all, let alone "a lot closer." How do you figure that?
There are word of frequently used every day objects that have MSA names only known by specialists, or don't have MSA names at all. So using pure MSA to teach practical every day language isn't really an option. (PS: I'm not a contributor to this course. I'm a contributor to the German for Arabic speakers course. So my opinions here don't have any direct influence on the course's content)
The easiest way for Arabs to make themselves understood among each other actually is using English or French, which are much natural to use for most people than MSA. Yes, Arabic dialects can be that different, and that's why I consider them different languages, and not dialects. Their differences are much greater than that of Romance languages (I know 6 Romance languages).
Anecdotal evidence isn't evidence at all. Anecdotal evidence is just a few data points on a curve, and as anyone who has ever tried to fit a curve to a set of data points knows, trends cannot be predicted from just a few data points. Actually assuming we don't know is much safer than assuming we know based on those points. Little knowledge is dangerous knowledge.
Regarding research of mutual intelligibility, I invite you to send me a link to one and we can discuss its merits. Not all research is fact. Doubt is an inherent part of science and criticism is always welcome.
We have a lot of Egyptians in Lebanon and I'm Lebanese, so I've been surrounded by both dialects all my life as well as studied MSA at school and read it in newspapers. Egyptian is so different than MSA, that Egyptians themselves are trying to make this difference official and naming the language Egyptian. It's the only Arabic 'dialect' that has its own Wikipedia entries. If Egyptian was so close to MSA, why would Wikipedia decide to allow for duplicates of such close languages?
In any case, I haven't been able to find scientific research on the matter, so I cannot give you a reliable answer. I'm just sharing my personal experience with you, knowing that I'm someone who has studied a lot of languages deeply (not in an academic way), and who enjoys differences in languages and tries to learn from others as much as I can. I don't consider this evidence, but it's all I have to offer at this point.