Is they anywhere I can move my machine into 2021 and test to see what will I see in IE or Edge Windows 10.
I just would like to know what message which will be display on screen.
Bear in mind Microsoft may still issue more updates that specifically disable Flash in IE and/or Edge. These may not have been released yet, so it isn't a true test.
Yeah, future updates to the major browsers will remove support for plugins entirely.
Each of the major browsers has their own roadmap. They're all linked to from the original Flash EOL email back in 2017.