You are 💯 correct, and impressive you know the details!
The funniest part about it all to me is that AT&T bought Warner / HBO in 2014 - 2017 for 80+ billion at the height of Game of Thrones popularity (after winning an antitrust lawsuit against the merger).
Then season 8 happened, and in 2018 AT&T immediately sold Warner / HBO to Discovery where they merged into the David Zadislav Hollywood cluster fuck they’ve become.
The branding then unbranding of HBO to MAX was after the Warner Discorvery merger. They just have no idea what to do with their IP as they have no experience making or working in the creative industry.
“King Arthur and the Knights of Justice” is what you’re looking for - and more specifically the absolute facemelter of an opening song they had for the show:
https://youtu.be/gjbWDjzTM0A
The whole series is on YouTube for free BTW! Not a bad watch either. Still pretty fun, but certainly dated for the time.
That opening guitar still gets me decades later.