Translation:Do you want to order?
The answer to your question is complex. I suggest you read this well-written article https://www.chineseboost.com/grammar/xiang3-yao4-xiang3yao4-difference/
Yes, the correct answer should be "Do you want to order" which is correct English and "...you all..." should also be accepted, but not the standard answer.
Amazed how many people on Duolingo don't understand that "you" is the correct second person plural as well as singular pronoun.
I don't think 要不要 insinuates "or not" at all! This is just a grammatical structure very common in Chinese! Adding "or not" in English strongly suggests a kind of mood (impatience maybe) that is definitely not present in the Chinese sentence!
I agree that creating this analogy is useful to understand the logic behind the sentence, but I think it should be avoided in the translation!
I do agree with you on the 们 part, though!
What I learned is the following: Regardless of how many tones, every third tone but the last becomes a second tone. 3-3-3 -> 2-2-3 In theory, anyways, in reality a speaker's cadence might break up larger chains of third tones into multiple smaller pieces of everything-but-the-last-tone-is-a-second-one. 3-3-3-3-3-3 -> 2-2-3 [break] 2-2-3