The way this watermarks are usually done is to put like white text on white background so for a visually impaired person the text2speak would read it just fine. I think depending on the word processor you probably can mark text to use with or without accessibility tools, but even in this case I don't know how a student copy-paste from one place to the other, if he just retype what he is listen then it would not affect. The whole thing works on the assumption on the student selecting all the text without paying much attention, maybe with a swoop of the mouse or Ctrl-a the text, because the selection highlight will show an invisible text being select. Or... If you can upload the whole PDF/doc file them it is different. I am not sure how chatGPT accepts inputs.

I mean it’s possible yeah. But the point is that the professor should know this and, hopefully, modify the instructions for those with this specific accommodation.

I would think not. The instructions are to cite works from an author that has no works. They may be confused and ask questions, but they can't forge ahead and execute the direction given because it's impossible. Even if you were exposed to that confusion, I would think you'd work the paper best you can while awaiting an answer as to what to do about that seemingly impossible requirement.

You're giving kids these days far too much credit. They don't even understand what folders are.