Rear doors - I can see them fixing the doors if they get enough dealer complaints and the fix is a relatively simple hinge redesign (low investment plus high return on customer/dealer satisfaction)....but if it's more complicated than a simple hinge design, then it will be a MMR or Gen3 issue.
Tailgate lock - I don't think Honda will intro a tailgate lock next year, no matter how much the (relatively small) RL market demands it. If it is addressed by the aftermarket, Honda will deem that 'good enough' and maybe work on an in-house solution by MMR if it isn't too much effort. They have enough work to make the tailgate reliable in the first place. Gee-whiz efforts like IBA seem to be more important from a marketing standpoint.
Headlights - Joe mentioned a very good chance of MY18 Ridgeline getting updated headlights, or LED headlights across the board, in response to the IIHS report. He also mentioned Honda has a renewed interest/emphasis on safety items, so perhaps some of the nannies will filter down from the E/BE. In that vein, there is a possibility of trim realignment to something more sensible, like the Canadian trims levels.
Transmission - This one is a wildcard. As I mentioned in other threads, I think it hinges on several variables, such as 1) contractual issues with ZF, 2) readiness of the 10AT, 3) whether they want to play brand/model games with who gets it first. If it gets significantly better MPG, they will want it in all lines ASAP, to get CAFE credits which they can sell for much-needed cash. Since Ridgeline is a low-volume vehicle, this may not be a big deal; however, Honda may wish to keep claim to best-in-class MPG claims, esp with GM upping the game with VCM and a new tranny for the Coloranyon. If we get the 10AT, I hope they do not implement Start/Stop (or at least make it defeatable), and I hope they make it push-button to free up the center console for more/better storage.
Off-road - Not going to happen anytime soon. If anything, maybe see active suspension by the time Gen3 arrives. AS could give you a 2" lift at low speed that turns into a 2" drop at high speeds - best of both worlds if they can work out suspension issues (easier to do with BOF).
Appearance package - could differentiate more from the Pilot if the RL sells well, but won't happen until MMR at earliest.
For MMR, I would expect to see things like a tow package / work truck (Contractor Special), as well as different cab/bed configurations, like extended cab with 6.5-foot bed. Joe mentioned that a significant benefit to the new platform was the ability for different configurations, so I'd expect Honda to take advantage of that, if the truck proves popular.
Engine - Honda is big on hybrid tech, and we might see something new for the MMR. I wouldn't mind a turbo-four from the Civic mated to hybrid electric drive, with on board user-friendly generator package to sweeten the deal (would be major hit among contractors, campers, farmers, etc. Lkke it or not, the V6's days are limited.
Looking at the big picture, I see the possibility for Honda to update models quicker, if their computer-simulated R&D proves reliable. This could mean a Gen3 instead of a MMR, or maybe a MMR in 2019 and a Gen3 in 2021. Sounds wishful, but I think it is very possible, especially if the truck proves popular. Increased possibilities if the truck goes global, as per Honda's original plans. They can always build or reconfigure existing plants for more RL production, as well as build RL's overseas for overseas markets. Global platform means high-priority, non-filler status, with quicker updates and much better QA/QC.
Just my $0.02 (with a healthy dose of wishful thinking thrown in)...
