Early returns on the 10.2 update for me are not good, both of my watches seem to be continuing to lose battery very quickly. I'll keep monitoring it, maybe I'll experience that mythical situation where it's bad at first and then it starts being okay after a few days.
My Apple Watch SE 1st generation that I've had for 3 years has battery health at 80%. Even still, prior to 10 it was getting me through the day, though sometimes barely. But this battery drain issue is so bad that I acquired another SE 1st gen to get me through the day. I bought it used and when I bought it a month ago the battery health was 100%, now it's down to 92%. So if there were any question that this issue is destroying batteries, there is an incredibly strong indication that this issue very much is taking a toll on these batteries.
You shouldn't need 2 watches to get through the day. This is absolute garbage on Apple's part.