I don’t think the Roadhouse party was meant to spotlight the other characters. To me it just sounded like after Sam and Dean have their big reunion moment, they head inside to the party. It’s literally just a montage of Sam and Dean talking and laughing w/ these characters thst they’ve helped through their life. I think that was the intention. Show all these lives that Sam and Dean have touched through the years. Which is while Jimmy Novak exposition dump would have killed the emotion of the scene. But like I said, I don’t think the intention was to take the spotlight from Sam and Dean. They were essentially going to be background extras.
I mean, I think there's also a difference here between what the intent might have been and what the result would have actually felt like, IMO.
In Dabb's head, I think he really believes that he and his team actually wrote for and about Sam and Dean the whole time, because that's how he talked in interviews. But it sure didn't feel that way when the show was playing with trying to make Sam team up and joke around with Lucifer. When Dean suddenly had 'antibodies against evil' so that he had no reaction to walking into hell or trauma from being possessed (or need to have a real conversation with Sam about his own possession trauma). When they had Sam ask why planets were round and Dabb wanted to just slap him in a romance with Eileen after being manipulated into one by Chuck. When they fumbled the Michael!Dean arc in the exact same way they fumbled the Demon!Dean arc by just abruptly moving on to the "more important" things they supposedly needed to get to. Et cetera.
Actually, if you read the rest of the article [X], it wasn't Sam and Dean have their moment and go into the Roadhouse, but Dean drives up and goes in and finds Sam in the crowd. So yeah, I think Dabb would have slapped literally every possible person in the room, gave long lingering shots to some "fan favorites" - for which Sam and Dean's interaction would have to be pared down, naturally! As well as put in plenty of shots of the band because you're not gonna waste that cameo, right? But because Sam and Dean were together in the middle of it, it's totes about them, isn't this so satisfying and awesome just like the last four seasons of "cool" over substance?!
I feel like so much more of Dabb's issues were less a failure of intent so much as a lack of appropriate focus and definitely a lack of necessary skill.