Wed Feb 17, 2016 3:12 am by strop
I'm not a dev but I've been around long enough that I can answer this for you.
It may take a while to go through the full process of development, but that nobody else here is complaining about the prospect of certain features being designated DLC demonstrates how those of us familiar with the game's scope and its progress understand the conceptual and structural limitations of the original vision. To get that, you'll have to discover what the game was intended to be.
The things that are considered DLC are things that the developers acknowledge are interesting and hopefully will be developed, but are a much lower priority due to the balance of their being sufficiently removed from the original concept (cylinder and camshaft operated, petrol powered internal combustion engines) that it would take significant amounts of time for relatively minimal gain to the game's overall scope. Wankel rotary is a perfect example of such.
Keep in mind that we're this far into development and only the scenarios (which are a small part of the game) and the sandbox are available. Things are actually progressing nicely in that we have several engine types and the basic mechanics for building a car decently is there and working, aside from the fundamental "component modules don't like to talk to each other." The Tycoon campaign part is the major bulk of the expected gameplay, and the foundation for this part hasn't even been integrated into the UI of the public release. This involves integrating the fiscal, engineering and management components and (I think) developing procedurally generated competitor market for the continuum of 1940-2020. That's what they have to concentrate on, plus porting the game to the new Unreal engine to iron out module communication inconsistencies plus a whole lot of other optimisations, plus adding in the rest of the cylinder formats (V12 turbo, new modern turbo systems, supercharging, V16, i3, V10- this is more time consuming, data-intensive work than most people imagine). The tycoon framework part alone will probably take until July...? As for the rest...
After all that, then they can think about other stuff. Like Wankel rotaries. But I don't think anybody else here is going to be particularly looking for waiting several extra months for that while all the above needs to be done, hence later, as in, DLC later. There's no cash milking here as far as I could tell, just trying to get the job done.