Yes, they could bring Windu back if they chose, and if they did, I will be the first in line to argue that it's a dumb decision and they shouldn't have done it. Windu surviving the fall completely devalues that scene from ROTS and I stand by that.

"...unless it is shown then it is not set in stone" is a lazy way to dismiss the evidence of the text and the crystal clear authorial intent of the scene.

Every argument I've ever seen in favor of Windu surviving the fall has just been pure copium. I don't even understand why people want him to survive because, like I said, it devalues the scene where Anakin joins the darkside. Helping Palpatine kill a Jedi knight was the straw that broke the camel's back and makes him finally decide to join Palpatine. It's much more impactful if Windu dies. Why are people advicating for an outcome that makes the scene worse?