It’s ironic that you hear rumours of Apple killing products by increasing battery drain in a FW update, then you see it for yourself.
my Apple Watch 7 worked fine, no problems at all and I got 3 days use before it needed recharged. After updating to watchOS 10.2 - my battery only lasts 10 HOURS! So yes I take that as definitive proof of the FW tactic to boost sales. Of course Apple won’t keep this post up - they actually have trolls to scour this site to remove FACTUAL answers that they don’t want you to know about - even though it’s true, it’s “a secret” so they'll no doubt remove it. But yes it’s affecting everyone who DOESN'T have one of the latest Apple Watches (surprise surprise)…….
furthermore, YOU shouldn’t have to fix an issue that THEY have created, I.e being told YOU need to/should try to unpair, delete then redo it all over again. They created this problem so it’s their job to fix it not yours. God knows they make enough money to offer a far better support platform than the copy and paste (from other websites) gang we currently get.