I ran into some issues with date complications on my faces. Seem to recall I got things working again by rebooting both phone and watch and then re-adding the complications on the respective faces.
When I attempted to upgrade to watchOS 7 I found I did not have enough storage free. Deleting apps did not provide enough space so I envy anyone that was able to without going through the process of un-pairing and re-pairing the watch as I did. Having said that it also avoided a lot of the issues that others seem to have experienced. So if you have serious or annoying problems either after upgrade or update to watchOS 7.0.1 I suggest you simply un-pair and re-pair the watch. This will erase the watch then you can upgrade/update and restore from backup.