We have never gotten a room ready text while at airport or on ME. We usually arrive late morning. At times, we have a room shortly, other times a several hours. We have never had to wait until 5 or later.
One we were doing a split stay, checked out of BLT and was waiting for room text for AKL. Went to MK for a bit. Nothing , nothing. Went over about three. Our room was ready but it was not what we were expecting. I was told since we were the last one to check in (even though we did online at least a month prior), there was nothing they could do. They did offer to move us the next day, but we didn't want to pack up and move again.
The bad part was it was the last room on the savanna, right next to the pool. We got all the pool noise, the pool games, the compressor in the morning for cleaning. We are sit on balcony, drink coffee, read books type people.
From now on, I'd check in with the front desk if we don't hear anything.