MSA OR COLLOQUIAL ARABIC
I wish to learn Egyptian Arabic. Which dialect is Duo teaching please?
There are resources for learning Egyptian, Syrian, etc., but not here. Duo is teaching MSA which is the only language that spans the entire Arab world, and is also the language of the media.
There are regional differences in every language, but in the Arab world they are quite different, and Egyptian, you will find is profoundly colloquial. So although the words may be the same, the way that they are used will not necessarily be the same.
This is not to say that studying MSA would be a detriment to learning Egyptian. For instance, in Egyptian they refer to the hippopotamus as Mr. Cream, but the words Mr, and cream, are the same words used in MSA across the Arab world to mean Mr and cream. So knowing what the words mean would not be a detriment.
Jumping straight into Egyptian from English without MSA would be kind of like plunging straight into Cockney from a foreign language.
I've over answered your question, but I hope the information helps.
I think if you want to learn Arabic for living in a special place then you can learn their dialect. But if you want to be flexible for business and/or vacation and so on then it might be better to learn MSA. With this you can later on digging deeper in any dialect which is needed or you will find out which is becoming your favourit one. It should be easier to learn first a proper grammar and way of speaking and then go into any dialect. And honestly, for me it sounds every time so strange and horrible when people who live in my country can not speak the language in a proper way but use a very strong dialect.
MSA is a bit archaic, because it is based on classical Arabic, but it is not yet irrelevant. It is used in books, newspapers, radio news, internationally, for business, etc. I don’t think it is likely to go away anytime soon because, much like Martin Luther’s German (created by ML as a universal German, no one’s lingua franca at the time, yet the German learned universally at school today), it is far too useful.
I suspect that some online “polyglots” are a lot less proficient in MSA than they would like us to believe, or perhaps that they believe themselves to be (I’ve watched a few painful videos). Also, I suspect people of taking their own limited experience with using MSA, perhaps not proficiently, or in a very limited geographic area, and then making broad generalizations based on limited experience.
Egypt is a big country with a vast population. Yes they use dialect (more than one), and it is possible to watch movies in Egyptian. Still, people who read books and newspapers, listen to the news, travel, go to school, etc., do have experience with MSA. I have known Egyptians who were very proficient at MSA, and Naguib Mahfouz famously wrote his Nobel earning books in MSA, not in Egyptian.
I think the hard truth is that if you want to travel in Egypt extensively, or live there, you will want some dialect as well as MSA, not one or the other. As to which to learn first? I personally think MSA would be easier to learn for these reasons: more available resources, more widespread usage throughout the world, more grammatical (dialect is dialect because it doesn’t follow rules, though this is quite arguable), far easier to become proficient in (remember my warning that Egyptian is profoundly colloquial). I also think the dialect would be easier to pick up in immersion, and would take a lifetime of immersion to master. Still, if you feel you have more of an affinity for Egyptian, or if you have some opportunity to immerse yourself in the dialect, then by all means learn that first.