Google has confirmed which existing smartwatches will receive Wear OS 3, its 'new unified platform'. Only the TicWatch Pro 3 and TicWatch E3 are eligible, leaving the likes of the Fossil Gen 5, Gen 5E, Oppo Watch and Suunto 7 behind. Neither of Mobvoi's latest smartwatches will receive Wear OS until deep into 2022, either.
https://www.notebookcheck.net/Wear-OS-3-Google-confirms-its-new-unified-platform-ditches-all-but-two-existing-smartwatches.552087.0.html