Samsung and Google may have agreed to merge Tizen OS and Wear OS, but current Galaxy Watch smartwatches will be left on the older Tizen OS platform. Samsung will update the Galaxy Watch Active, Watch Active 2 and Watch 3 for at least three years from their launch date, mind you.
https://www.notebookcheck.net/Samsung-commits-to-three-years-of-updates-for-current-Galaxy-Watch-smartwatches-but-no-Wear-or-Wear-OS-upgrades.540131.0.html
That's very good news, because now i'm sure my Samsung Watch 3 won't be "upgraded" covertly to WearOS. Till August 2023, i have plenty of time to evaluate other choices, and it won't be a Samsung Watch 4 for sure.
By the way Samsung, till Aug 2023, i hope to get Blood Pressure and ECG as advertised initially. I'm not in a hurry.. Believe me, i'm not living in an obscure country on the map.