@ClassicRockerDad, I don’t think that it is unfair. Universities accept each student based on the academic package they present, and the deal includes completing that package. Other students packages are completely irrelevant.
If the OP can’t successfully complete the package, he needs to take responsibility for it, and deal directly with the university.
@collegemom3717 West Virginia admits 72% of it’s applicants. Very few students nationwide attempt BC Calculus. It wasn’t likely a factor in OP’s admissions.
On the other hand, Berkeley admits 17% of it’s applicants. If OP were applying there, the attempt to take BC Calculus would likely have beeen a factor in admissions.
I agree with the OP that it would be unfair to penalize him at West Virginia for trying something hard. I also want to emphasize, that it would not surprise me in the least if West Virginia had some blanket policy and rescinded OPs admission anyway, as unfair or illogical as it may be.
Most of this thread seems to be generalizations and speculations, or arguments about fairness or unfairness.
But what the OP really needs to do is:
A. Read the admission offer’s conditions to see whether s/he is in a situation where WVU may rescind admission on the basis of earning a F (or D) in a senior year course, or has some vaguely worded language about maintaining one’s academic performance in senior year to avoid rescission.
B. If rescission is a possibility (likely) and the grade actually ends up being an F (or D), contact WVU immediately to find out of rescission will occur in his/her situation, and (if so) whether there is anything else s/he can do to avoid rescission. Better to do this now rather than surprising them later with a final high school transcript with an F (or D) on it.