Yeah, that makes sense and is highly probable, but with this series, I am imagining how I would build the series from the ground up, with a revamped roster and stages to match. As for the Mario Odyssey stage, I imagine that they could have the Cloud Kingdom as a more straightforward, competitive stage, since staying faithful to the layout of the kingdom would lead to a simple battlefield. For attention to detail, maybe the Odyssey is in the background, coming and going throughout the fight. Just an idea. I'm with you on E3, though; I'll probably write a piece predicting Nintendo's showing this weekend.
RE: How I would Reboot Super Smash Bros. Part 4: Mario & Zelda Stages