As an update, Truth Social's posted Mastodon source code has not been updated since my initial post in this thread, and has seemingly not been updated since at least June of 2022 (compare: http://web.archive.org/web/20220614001551/https://opensource.truthsocial.com/mastodon-current.zip). So if they're still using and updating Mastodon internally, they're no longer complying with its AGPL license at that link.
glynmoody
markhughes
shanselman
kcarruthers