I don't think we got any other "name only" reveal that I know of. The big guest host and reveal was the Xformers crossover, which is fine, but seems a bit like salt in the wound for O-ring enthusiasts.
I really don't think there would be much new that they could develop from full sized military hardware at that scale, at least not for wide distribution (maybe for a HasLab). Anything larger than a Humvee would be mighty expensive I'm afraid. The line offers a bunch of small vehicles from back in the day that already fit the bill. Modernized (but still fully recognizable) Devilfish, Polar Battle Bear, FANG, ASP, CLAW, Sky Hawk, Ferret and AWE Striker all come to mind as low hanging fruit.
I think the vehicle/set theme should be to have equal opposites where in a given series they release the enemy's response to each. There might be opportunity there to offer new foils to some of the equipment that lacked those in the original run.
I like your set pieces idea for this scale too - crew served/stationary weapons, bivouacs, checkpoint kind of things. Heck, even battlefield environmental stuff would be worth considering - figure stands with battle scars, general building debris, rappelling gear, etc.
As for new vehicles, I think they would have to be limited to Jeep sized and smaller. Perhaps a version of a special ops UTV since that's real world, but that's only marginally smaller than an AWE Striker. Joe already has the RAM for a cycle. Joe had jet packs before they were a practical thing in the real world. I can't think of anything in a reasonable size beyond those that have become a regular implement since. Joe was ahead of the curve.
As for the VAMP and larger, I think those would likely have to release individually with a particular wave (with driver included) and the more substantial ones as HasLabs. I agree that anything they do with the VAMP must at least start with the iconic (OD) frame as the base. Worst case, if you don't like the add-ons, those could be removed and set aside.