This isn't correct. They voted to recommend against the MMRV vaccine which MMR + Smallpox vaccine. Typically for under 4's these are done separately in something like 85% of cases unless the parent specifically requests them together.
So not much is changing regarding the MMR vaccine
We're mandated to use it at my work. For unit tests it can really go wild and it'll write thousands of lines of tests to cover a single file/class for instance whereas a developer would probably only write a fourth as much. You have to be specific to get any decent output from them like "write a test for this function and use inputs x and y and the expected output is z"
Personally I like writing tests too and I think through what test cases I need based on what the code is supposed to do. Maybe if there are annoying mocks that I need to create I'll let the AI do that part or something.