Implemented in both C++ and BP
An RTS pawn, units, buidings, fog of war, minimap, resources, factions, harvesting, group selection, etc.
I know there are community stuff out there, but I’d like to see stuff like minimaps coded into the engine. Just IMHO anyways 
I seconded this. It is actually a very good idea especially a lot of people would want to start with RTS. 
There are so many things a RTS would have to have, it wouldn’t be a Template anymore.
Needing a Grid system to put buildings or even use the same system for positioning units, Fog of War etc. Those are not really user-friendly stuff that can be implemented easily or implemented.
Note that I am not really against the idea, but it might be “asking too much for a template”. 
I wouldn’t say no if they decide to do it though. I always wanted to create a Tiberian Sun game. 
Im agree with @Achilleon. Problem is some stuff cannot be easily made in UE4, so far i didnt even saw any fog of war on UE4, but besides that, RTS is basically a Top Down template + dynamic UI, everything has a remote player control over some AI.
There are a few fog of war experiments but they seem to be either very hard to implement or just very costly, or just doesn’t look right. It’s funny, one could say it would be easy but maybe it is easier with fixed camera angle. 
Cough cough RTS Toolkit Cough cough
Seriously, though, I know it’s not perfect for everyone’s RTS but it is really as close to a template as I could get it without being far too user unfriendly. The only real disadvantage of the RTS Toolkit, I think, is the FoW isn’t as great as I’d like it to be. It works fine but it only mimics light. The main goals of the RTS Toolkit were #1) Create a foundation that people could use to learn about how an RTS might function and #2) Give a good intro to blueprints and interfaces.
I’m the developer of the RTS Toolkit, by the way.