I gotta say, when Gia's Marvel fanfare came up at the beginning of Wandavision this past January after 18(ish) months, I just about lost it. It was like seeing family again.
That didn't hold a candle to this. There has never been an official release of G's fanfare. It would be nice if they'd put this one someplace.
I don't really know if it's good. I do know that it's perfect.
Most of the music in that video is generic trailer music with a few seconds of Giacchino’s Marvel fanfare thrown in. And no, the Giacchino’s fanfare has never been released commercially.