Ideally, someone accepting your PR shouldn't gate working on the next one. I would be more interesting in figuring out what process issue means you can't start work on the next item than in making everyone respond to PRs in real time.
No, but I've seen folks get laid off as a result of this. Granted they were in a PIP but they'd met the conditions established within with exception for accepted PRs, y'know points. So when their PR wasn't approved before standup the following day (end of sprint) they were let go that afternoon despite having done their work to the satisfaction of the PIP such as they could.
That's not an issue with remote work / TZ differences. That's an issue with stupid management. If the review was solved, they'd find some other system to abuse.