Because Meta is already illegally scraping hospital websites for your records.
Sorry, but this is just bad web design from the hospitals. This pixel tool doesn't magically appear on websites without being put there deliberately. Literally any tracking tool can capture this stuff on any page that a developer puts it on. This is 100% the fault of the programmer at the hospital (or the admin that made them do it) that decided to put tracking cookies on sensitive pages.
The hospital administrators decided it was more important to get their precious reports on usage from Meta's portal than protecting their patients.
I'm pissed that I've had to defend Meta here, but this one isn't on them.