IMO that's the only reason for employers to offer "unlimited PTO" schemes.
> Does explicitly saying "4 weeks" put them back in the hook for that, or does saying "expect" get them back off the hook again?
Hmm, at my most recent employer, I heard passdown from my manager that "the man above" (VP) had "guided" that 5 weeks was the ceiling for "unlimited" and that TPTB would look askance at anyone taking more. But this was all "off the record".