To be honest, I’d like to see them come back. But for new patrol zones, I’d want this: https://imgur.com/a/kQC4MzY
Cosmodrome will be back, I'd bet my console on it. Dreadnaught, that's a little iffy but I wouldn't doubt it. It's a lot less work to use all the distant imagery, sky, mountains, buildings, etc. and just add some close up structures than it is to build a while new open world area from scratch. Bungie is always trying to do things on the cheap.