If the mobile game is successful they might revisit the franchise proper. C&C3 and RA3 are too far detached from their predecessors in themes and story lines and atmosphere, etc. If you wanna continue something you gotta stick with the original writer's vision and expand on it properly. EA's C&C 3 and RA3 basically ditched the previous world building. Still fun games. Generals is cool 'cause it's its own thing.
Best thing I'd want is a retcon of C&C3 & C&C4, and make a new game set right after Tiberian Sun Firestorm, but this time, follow the lore properly. There was a fan project called General Failure's Tiberian Twilight Initiative. He made some big concepts and nice 3D models, and he was a true lore nerd of Tiberian Sun & Firestorm. He crafted an epic story and awesome unique asymmetrical game play.
He had planned the game to portray Earth totalyl infested with Tiberium, like it was in C&C 3's Red Zones, only cranked up to 11. Tiberium has completely infested all soil, well, 90 percent, almost. 4 factions were planned: GDI, Nod, the valiant warriors, and CABAL/Kane, and Scrin, the super soldier factions. While Scrin & CABAL embraced tiberium, GDI & Nod both had their own ways of evading tiberium infestation and protecting their own colonies of civilians.
GDI had bunker bases, had bunkers attached to their buildings, bunkers for Mechs, like Titans equipped with cannons on both sides, could stand inside its own bunker. They had gigantic tiberium harvesters, with even bigger Carry-Alls airlifting them. Railgun and Firestorm Defense tech abound. They used gigantic naval vessels, submersible aircraft carriers. Since tiberium can't fuck with water too bad, GDI had underwater colonies.
Nod has underground tech. They build their bases underground; the in game interface allows players to transition the view from on surface to underground areas real time, amd both worlds interact with each other. Nod players build tunnel networks, with fast railway trains (like the Montauk in Tiberian Sun) moving units to elevator entrances to/from the surface. Enemy players have to find ways to collapse underground tunnel networks to combat Nod's sneaky rushes. GDI Disrupters can shoot sonic shock waves into the ground and collapse tunnels. Nod has even deeper underground colonies lore wise for its civillians.
CABAL/Kane was the most epic monster in it all, even compared to Scrin. THE toughest untis of all. This is all the information I remember from Generals Failure's Tiberian Twilight Initiative, fan sequel to Tiberian Sun. It was 3D RTS, and he made some really cool models. Now this is YEARS before EA even thought of making C&C3. unfortunately His website is long gone. It was so cool, he barely got into the CABAL (who is lead by Kane - Nod is no longer lead by Kane) and the Scrin before he abandoned it all. :(