Not that this should comes as a surprise to anyone, but the following article contains spoilers for Bill & Ted: Face the Music. Read at your own risk.
Bill & Ted Face the Music had been in the works since 2010 and finally saw the light of day this year. Given the amount of time the movie was being written and re-written, it stands to reason that there were plenty of endings prior to the one that ended up in the movie.
Co-screenwriter Ed Solomon told the The Collider Podcast (via MetalSucks) that he and his team had to rethink the original ending, which wasn't great.
"Our first draft that we wrote in 2010, the ending of the movie was really small. We had a scene at the beginning where 20 years ago they had put $100,000 down to rent the Rose Bowl for their triumphant 20th Reunion Tour, and when we meet them in the movie when it opens they have sold literally zero tickets. We had a scene where they went to negotiate with the guy to try and get their money back and the guy was like, 'No, you're stuck'. The whole movie was moving towards this ending, and the guys were thinking, 'Well obviously it must be at the Rose Bowl. Obviously we're gonna fill the Rose Bowl with this triumphant song, we just don't know how.'
"And the whole movie happens like it happens, they go into the future, their lives get worse and worse, and they arrive at the Rose Bowl and it's empty. There's no instruments there. It didn't happen. They failed. And they go home and they sit down in their living room, and you're like one minute from the end of the movie. And they realize they failed, they feel like they failed, and then they hear music coming from the other room and they walk in and they look and see their kids and they realize it was never them, and the movie's over."
Solomon also adds that there was a really weird ending involving Santa Claus. Which would have been even worse.
"We had a version that I really loved that did not last very long, it lasted for one draft. Bill and Ted had to get instruments to everyone in the world throughout all space and time in one evening, and they were like, 'How are we gonna possibly do that? We have no way to do that!' and they say, 'Well we can't, but there's one man who can,' and then we cut to, 'Ho ho ho!' and a sleigh, and it was Bill and Ted and the Princesses on Santa's sleigh using Santa magic because Santa can go around the world in one night.
"They were actually going down chimneys and they were having a great time, and it was this crazy montage that we had written. That did not last. I thought because the antecedents to this movie were A Christmas Carol and It's a Wonderful Life, so maybe it's a Christmas movie and we have Santa at the end? I think Alex Winter liked it briefly, but I don't think anyone else thought it was a good idea, then we ended up scrapping that."
Overall, I think the ending that ended up in the movie was the right one, and it was incredibly touching. Check out the full podcast episode below, and make sure you check out the soundtrack featuring Lamb of God and Mastodon too!