Using the SDKBrowser application to test, I'm not able to right-click inside any of the rich text editors on Windows to bring up the context menu. I tried setting AutoGenerateContextMenu = "True" but that didn't change anything. Maybe I'm misinterpreting the documentation but it seems like that property should enable right-clicking?
I realized I was using an older version of Telerik UI for MAUI. Updated to 6.8.0 has fixed the issue.