There are more than a few folks who have always maintained that the verbiage "check-in
begins at 4pm" meant that you could check-in no earlier than 4pm, but didn't mean your room would be ready
by 4pm.
The other camp maintained that check-in beginning at 4pm meant (or at least
should mean) that you can't check in before 4pm, but rooms should be ready once check-in begins (a reasonable expectation in the hotel industry, I think). That's why check-in doesn't begin until then, because they need until then to get rooms ready. So if they need longer than that to get rooms ready, then check-in doesn't
REALLY begin then. You can check-in to the
lobby. You just can't check-in to your
room!
Kind of reminds me of this...
The statement "Rooms will be ready between 4pm and 6pm" does eliminate the ambiguity of what is meant by check-in
beginning at 4pm. It establishes that your room
will should be ready no later than 6pm. This essentially tells us that rooms may not be ready until up to two hours
after check-in time. If rooms aren't ready for two more hours, why is check-in at 4pm?
If it's acceptable for rooms not to be ready until 6pm, how long before we're told that they won't be ready until 8pm? Or 11:59pm? That example might be hyperbole, but in principle the room being ready 8 hours after check-in is not different than it being ready 2 hours after check-in. If check-in time isn't defined as the time you can check in
to your room, then it's just an arbitrary time. They might as well say that check-in begins at 6am, but rooms won't be ready until 6pm.
In most people's view, "checking in" to a hotel is synonymous with getting into the room, not merely letting the hotel know that you've arrived. Rooms being ready for guests to occupy is the only really relevant time.
I get it... COVID, short-staffed, etc. But this issue pre-dates COVID.