While Crash has been revealed, and obviously I have no idea whether you guys have made up your mind on a Crash stage yet... but I had an idea for one that might work, so hear me out I suppose!
Firstly, since this is a prominent Nintendo-based game, I figured that Crash should maybe have something from his appearances exclusively on a Nintendo console. So, I turned to his small series of GBA games.
Which location is most known to people who remember Crash? It's really hard to say honestly, since Crash, unlike Mario for example, traveled to extremely varied areas, with each of them being unique from the others. How'd Crash do this? Through the use of a Warp Room.
Now I know this has been brought up before. People weren't too keen on a Warp Room because it seemed to generic and obvious, I guess. Well, a Crash GBA game has an option that makes use of a Warp Room-like area, while also being unique to the GBA games: N. Tranced.
The "warp room" of this game was actually a series of floating islands in space.
Here's the entirety of it: http://www.spriters-resource.com/game_boy_advance/crash2/sheet/7326/
As you can see, each various island is connected by small land bridges, and each main island has a different theme from the previous one.
This stage could work in a couple of different ways, giving us options that all make sense based on the source.
One, it could work like some may expect it to: take us to various levels, making it a transforming stage. This is obviously the best way to represent Crash as a whole in my honest opinion, but the workload of that may make it extremely undesirable given the workforce we have.
Another option is to make it a scrolling stage. You start off on the first island, then it slowly scrolls to the other islands, giving a change of scenery while not having to completely sprite a new background and foreground.
Lastly, you could very easily just make it a single stage, with no transforming or movement. This doesn't mean it can't be unique: maybe enemies can come from appearing portals in the background to deal damage to players, or perhaps since it's in space it can have lowered gravity of some kind. And since on a stream it was confirmed there would be an option to turn hazards off, it could also possibly double as a competitive stage with that option.
So yeah, just my two scents on an idea.