One daughter skipped one of her AP exams. I do not recall what the subject was but I would not be surprised if it were either AP World or AP Euro History.
There was exactly one consequence: She did not get AP credit for that one particular course on her university transcript. If I am recalling correctly, she did get AP credit on her university transcript for the other AP classes that she had taken.
I do not think that this made any difference at all in terms of getting accepted to very good universities, nor to her getting good financial aid. She was still 6 for 7 in university admissions, got into her #1 choice with good merit aid, did well in university, went on to a very good graduate program, and will be called “doctor” in May if all continues to go well. Edit: My point in mentioning the “doctor” thing is that in the overall perspective of one’s doing well in life one single AP test really does not matter.
High school students are under way too much stress in the US. If skipping one AP class reduces the pressure, then I do not see any problem with it.