This is very interesting…
I agree, it sounds like something has changed in the booking process.
I recently received an IB, from a newbie (”no trips yet”), who’s only communication was this:
My check in/out information says ”Flexible” for check in, and ”before 13:00/1 p.m” on check out. And I try to be very flexible on both. But none of my guests have ever taken it for granted that they could check in that early, if they wanted an early check in, they have always asked if ok. This one also took for granted he could check out 4 hours after my check out time. And also weird that he would not write ANYTHING else in his initial message, just ”inform” me of when they would be coming and leaving.
The bookings right before and after this IB, did not mention check in/out times at all. These were booking requests, I turned off IB after the above IB.