This is what the director had to say about the 7+ hour version of It
“We call it the supercut,” Muschietti explains. “It’s very early stage, you know, and we’re still discussing the format. It won’t be intertwined or anything like the way it’s in the book. But it will contain all the scenes that were deleted from both movies for pacing reasons, and we’ll hopefully have new material, which is stuff that I haven’t shot yet.”
On the subject of reshoots, he says, “Yes, but it’s under discussion. We’re just toiling with the idea with the studio, but we’re not there yet. But it would be great. Imagine having, in front of you, the two movies, seeing them as a whole, which is something that I never did — yet — and, you know, recalibrating things and saying, “Okay, you know what would be great? Seeing Richie flying in the Macroverse. Or whatever.”