To me this is the whole point writer Kento Shimoyama is trying to make with this special (if he has one).
The guy clearly has one. He's written some dodgy filler, and reuses plots a bit too often, but he's almost always trying to make some sort of discernible point with his stuff. I think he's a writer to watch, and could be doing some really good stuff in the next five or ten years.
Rather Go-Busters ended the way Yasuko Kobayashi always intended it to, retool or no retool.
I really cannot see this. The ending of Go-Busters we got is probably
similar to what was planned, in terms of the plot points that happened, but there's no way it was meant to play out the way we saw it. No writer's vision is going to call for an ending so rushed, where things that should be major points of drama are hastily skipped over.
As long as she was the writer Go-Busters was going to adhere to a certain vision and making it more "light-hearted" or in step with traditional Sentai tropes of the 80s and 90s wasn't going to change that.
I think it would be kind of sniveling and sad for Shimoyama to write a script about Kobayashi's importance in her absence, don't you? I think it makes more sense for Shimoyama to be writing on behalf of the entire staff, cast and crew. He's making the argument that despite the absurd changes mandated by the execs, the show's many creators gave it a spirit that no outside force could take away.
The retooled parts of the show are just Go-Busters awkwardly pretending to be something it isn't (like the Dobutsu Sentai), and they will ultimately fade away from the fans' memories (as the Dobutsu Sentai does quite literally). He's making the argument that in the end, the truth-- what the show
wanted to be-- is what will endure in the fans' memories. And who knows? Maybe he's right.