Perhaps I’m missing something, but the link you have in the most recent post isn’t in your first post.
The first link in your initial post is this.
And this:
Specifically, he refers to the ability to transfer from an account upgraded with Shadowlands to one that is not. That should not be possible in accordance to how our Character Transfer system works.
The referral to Hacks is if you have information about the exploit. It is for investigation purposes, so our Hacks team can check it out. They will likely also be working with QA and the Game Developers to figure out how it was possible and to fix it if it is verified.