For the sake of conversation and speculation -
They will build what they are capable of building, and selling, at a profit. To that end, what are people asking for and how much are they willing to spend to get it?
Can they build and would they sell........
more RTs in different colors and feature packages? Of course.
An ST-Limited with the 1330 Ace? easy.
An RS with an ACE 1330? No need to. You want a premium touring engine, step up to a touring model.
a LEANER? Might sell, but how easy is it to build? Cost? Hmmm. Would it open up a new market and get current bike riders to convert? Enough of them? Looking at motorcycle sales, who is most likely to convert to three wheels? Spyder riders are either coming from bikes, or they are the "others". A leaner really only appeals to a bike rider, none of the others, so how many sport bike riders would convert? Sure it would be cool, I just don't think the juice would be worth the squeeze.
A less expensive entry model, with say an ACE 900 (90 HP)? They could do this, but how many "new" buyers would want this? Is it too "boring"?
And the hybrid, or full electric. Noble cause, but seriously, how many would they sell? Would it also be too boring? Added weight and complexity, reduced performance but added economy? Didn't we all just ask for MORE power from our RTs? Who in the world is going to buy one with LESS power?
Remember, the GS model came out before the RT. They tried to create a performance image before satisfying the touring crowd. But once buyers had a choice of GS/RS or an RT, we all know what happened as the ratio of RTs sold to RS and STs is staggering. Does that mean ignore the RS buyer? Sure hope not. To a snowmobiler, ATV rider, PWC rider, dirt bike rider the RS is the way better machine. Active riding style, more able to throw the machine around. To the side-by-side, cruiser bike or touring bike rider, they more often will opt for the RT experience, and this clearly is where the money is being made right now. R&D follows sales, unless a new segment or market can be created.
Then we have the strange advertising campaign with Drew Brees and Danica Patrick. Not RT exposure. One has to conclude they are trying to bolster or create a better image with the younger demographic. Younger than the RT owners, at least. I am almost surprised they didn't go for somebody like Dale Jr. instead, might have been a better investment.
OK, I am done rambling.