In Hong Kong, the hotels even have cancellation policies with "72 hours prior to 11:59 local time day of arrival". I find it weird that they use times after official check in time. I guess the above means if you check in at 3 pm on Friday, then you can cancel until 11:59 on Tuesday night?

Why have they changed them? I suspect they want to deny any Best Rate Guarantees in future as many OTAs will state 0:00 for cancellation and with the slightly different deposit policies it’ll be virtually impossible to make BRG claims with Hyatt.