I just purchased the new Apple Watch Series 6 and received it on Saturday (11.21.2020) - like many of the stories on these threads about the Watch app crashing, my watch worked great for a few days - then suddenly unpair itself from my phone (iPhone XS) on 11.23.2020, then when I went to open the Watch app, the app opens for a split second to a black screen and then crashes. This prevents me from re-pairing the watch to my phone.
I chatted with Apple Support over live chat this morning for over an hour and went though backing up my iPhone, updating the phone to 14.2, restarting the phone, restating the phone and making sure all the apps were closed, and still the issue persists. The support agent said they exhausted all their options and suggested I reach out the Watch app support team directly from the App store. I asked if I should do a restore from my iCloud backup (as I saw on many threads there that that would fix the issue). I did that and it still did not resolve the app crashing. After reading all the threads on here I believe there's not a good solution in the works - Apple has no mention of this issue and the support I received did not resolve it.
It's frustrating because it seems this has been going on for months. The 14.2 bug fixes explicitly mention that it will fix the watch app crashing, but it has not.
I feel defeated and cheated - I will be returning this watch today.