When the Oreo update landed for Huawei's Watch 2 back in February, many reported that it was disabling Google Pay (then called Android Pay). One month and one rebranding later, this issue seems to have been fixed. There are reports that something in the last few days has re-enabled Google's rebranded NFC payments for the Watch 2.
It doesn't seem to be working for everyone, but reports of success with Google Pay on the device are widespread. Both Android Wear (now Wear OS), and Google Pay were updated in the last two days, but so was Google Play Services.
Frankly, it's impossible to tell precisely what might be responsible for the return of Google Pay support, but based on reports on Reddit as well as statements from our own tipsters, a fix is rolling out in some form. Not everyone is reporting success, though, so if you don't see any updates available for your watch or apps and you aren't willing to wait, maybe try downloading the latest updates for each potential app. For your convenience, I've listed them below.
I can't guarantee that any one of the updates above will fix the problem, so if you aren't having any luck, you may just have to wait.
Google has finally made a formal announcement that helps to explain what we observed going on with Huawei Watch 2 users and Google Pay support outside the US and UK: starting today, Wear OS users in Canada, Spain, and Australia can all conduct tap-and-pay transactions with their NFC-equipped smartwatches.