Then how to read this article:
https://www.collegeconfidential.com/dean/accepting-a-waitlist-offer-after-depositing-elsewhere/
Note: the author emphasized “any” reason.
The tricky thing is the situation is created by the department/college (who is handling the scholarship) not the admission office/financial aid office who is handling regular admission/FA. You would think they should coordinate, but the realty is they didn’t, at least this time. Anyway, maybe the best practice is to ask for an extension from them admission office anyway.