On top of what you mentioned there's also these things from RA that are currently unimplemented:
Helicarrier - though even if we find ourselves with the necessary visual assets, implementing it as a fun unit to play as is going to be a challenge. (And it'd probably necessitate Soviets getting a helipad on Hostile Waters?)
Tech Centres (as in the teamed ones, not the neutral "three domes" Technology Centre currently on NBNW). Would probably need a new map as most of the bases on the current maps are too "full" to feature more large buildings without removing one of them. And then there's the question of what it would do and would that warrant a whole new building (we already have quite a few barely-useful buildings). I don't think just "props up your tech level by 1 point" would be enough.
Camo Pillbox. I'd probably just have these be tougher Pillboxes like they are in RA. The usual idea I hear about them, "why don't you just randomize defence placements so Soviets don't know where the camo pillbox is right away" somehow assumes that the Allies will know where their own camo pillboxes are right away, may be a hindrance to the Allies because the camo pillboxes may end up in a more suboptimal position compared to where they are normally (and there really aren't a lot of optimal spots since the maps aren't super open anymore), may also be a hindrance to bots (including the AI ore truck) since base defenses by themselves do not block pathfinding so every place where a camo pillbox could possibly show up would have to be blocked off from bots, snipers/V2s would easily be able to pick them out even if you give them a random hiding place because of the target box (which is visible to both teams unless you make it stealthed which may not look the best), and within a few weeks of play people will have already gotten used to all the random positions anyway.
I also hope in the future we can refine the way the Spy, Thief, Mobile Radar Jammer and MAD Tank work, they're all pretty niche in their utility. Maybe a better tactical niche for the Tesla Tank, Grenadier and Flamethrower as well.