Why? Up till the end of last year, congressional Democrats were trying to get the ACA expansions extended, triggering a government shutdown in the process. Even after that plan fizzled out, they were promised a vote to reinstate it, so for hospitals or whatever there was still hope that there would still be funding. There's no real reason why you'd expect everyone to get fired the day that OBBA was passed.

No, the major healthcare employers are trying to adjust their staff sizes immediately to avoid later crisis caused by this draconian hack and slash approach to federal funding.

the intermediate is that the cuts took effect in January.