Author of the original post here, thanks for the crosspost.
Update: the XDA thread is locked. A moderator closed it as “obviously a rant about something that occurred outside of XDA Forums”, after stripping about thirty of the primary-source links out of the post. The F-Droid forum deleted my account before my post there was ever approved.
So the write-up now lives where nobody can lock or edit it, and I’ll keep it updated there: https://opensource-compliance-gh.github.io/plus-messenger-gpl/
Commit log, APK hashes, the dex inventory of the unpublished org.telegram.plus package, the pinned “don’t ask for source” rules going back to 2016, the Huawei AppGallery listing, the moderation timeline, and a chapter that walks you through checking all of it yourself in about ten minutes. Every claim links to something you can open.
Took your advice and did this. Thanks for the heads-up!