While true, unless the OP is planning on attending a safety, s/he has no idea what the AP policies will be. Even guessing will be problematic, because while some universities will cap, the student can pick and choose which to apply to the cap to be most beneficial. Some (or all) of the 5 APs may be more desirous of credit than any already taken. Unless there is a course which will universally not get credit, I’m in the camp of signing up for the exams now, and then make decisions about not taking (assuming the HS does not require AP exams to be taken) until after college decisions are made. Yes, it may involve losing some money. Alternatively, one could gamble and register late and pay the late test fee.
The other thing to keep in mind (and I’m not a proponent of this, but other users have mentioned on other threads), people transfer colleges. So even if a score is not needed for the freshman college, it may come in handy for the transfer college.