Yes you can do that, I did make significant blueprint changes that you may want to port over if you are using the template as a base. 4.16 the only real conflicting differences are that the ObjectType is gone from the grip interface, and that in the blueprints the template now checks for GameplayTags to help control gripping logic (I guess the secondary grip type enum is also something to consider). However the base blueprints controlling the character got a lot cleaner and more feature complete as it was time for an overhaul of the template.
One big thing is if you are doing multiplayer then you’ll either want to turn off the adaptive networking or set default minimum net update frequencies on all replicated actors, as 4.16 now defaults to it being on.
I would suggest a separate copy of the template and porting over changes that you find useful, as well as looking at the examples of new usage.