I see it like this: anything that isn't 12-bar blues in this piece is essentially just original writing. Rough estimate puts this mix at ~135 seconds of actual 12-bar blues material.
The thing about a 12-bar blues jam is that it's characteristic of that kind of music to just play the "head" (the basic melody) once or twice and then launch into an extended solo section that could take up much more than simply playing the head once or twice at the start and once more at the end. If you and I got together and played C Jam Blues we could riff for like 8 minutes just going back and forth with solos, but that song that we're playing is still technically C Jam Blues if we play the head a couple of times at the start and the end.
Brandon's woven the head of the piece throughout this song, carefully reminding us, despite all the soloing and riffing material, that this is a remix of Brothers Bear. There's enough material here that sticks to the original chord progression to keep the piece on target, and the main melody does show up a lot throughout the piece. It's a good point to consider, but I don't think the ubiquity of the chord progression is grounds for rejection. Soloing and riffing is a staple of the genre. I think it's alright here.
All that said, I think it's a solid track. Good playing, good balance between elements. No complaints here.
YES