I'm one of those who has dead GW4 because of this problem. Unfortunately I am in Malaysia and Samsung Malaysia refuses to acknowledge this problem. Thus is refusing to fix the problem without charging just under $100usd.
I am a UK GW4 owner and affected by the issue. Watch was working fine after the update then I went on holiday and decided not to take it. While I was away battery drained and it went off. On my return it won't power up. I have tried on the Samsung Duo charger I normally use, the original one that came in the box and power share with my S22 but none work. I have opened a ticket with Samsung under warranty and they have sent a courier to come and pick it up today.
I will update this thread with the outcome.
Based on what I have read online it isn't affecting all watches (mine was a very early pre-order) and it seems to only happen when the watch has completely drained of power rather than just a reboot while the battery still has power. I suppose their testing just didn't catch this issue.
I have just confirmed on the Samsung website that here in the UK the watch is covered by 24-month/2 year warranty so I am not expecting any issues. I wonder though if they will just replace it.