I hope that they will do it similarily to Victoria 3 and release a big patch alongside each DLC that contains the main features and mechanics, while the DLC is mostly adding stuff on top of that.

E.g.: Something like the patch adds a system for industries and the DLC adds additional buildings, etc. to that system

Edit: I would prefer it to be less car-centric though. But it looks like cars and roads are going to be central to the game again.