The default value for the EnableAllowList setting will default to true after Jan 12, 2021 on all flavors of Flash Player. At this point, Flash Player will no longer load content from the open web. You can configure specific AllowListUrlPattern entries in mms.cfg. Check out the admin guide for specifics on how to do that and where to put the files.
For completeness, please check out the Enterprise EOL FAQ here for a clear and concise description of what's happening, your options and our recommendations: https://www.adobe.com/products/flashplayer/enterprise-end-of-life.html
And check out the Enterprise Enablement section in the Flash Player System Administration Guide (pp.28):
https://www.adobe.com/devnet/flashplayer/articles/flash_player_admin_guide.html
In terms of what other companies are doing, I don't think we should be speaking on behalf of anyone else. All of the major browsers will be removing plug-in support entirely in the coming year. We do not recommend running an unpatched or unmaintained Flash Player.
The statements and corresponding roadmaps for all of the major browser vendors are linked to from the original announcement back in 2017:
https://theblog.adobe.com/adobe-flash-update/