BarryGraham Google Workspace has always had issue syncing properly with Outlook in my experience. I have always had to help clients install the sync app provided by Google for emails to show, which only works with the regular Outlook.
Yes, it would be expected they will stop supporting regular Outlook, but there is no official announcement on this, and I doubt it will happen right away due to the lack of COM add-ins, which many businesses are still reliant on. Also the fact that there is a range of features they need to have live before they could consider the switch, like offline working. I think it is expected that we will see two different Outlook for quite some time. It has already been like that on Mac for 4 years. Macs still have both a New Outlook for Mac and regular Outlook today. They have never turned off the old Outlook in Mac. So tbh, I am doubtful we will see the old Outlook be disabled or loose support in the next 6 months.