On the one hand, I agree with what Moe said about Satoshi needing a strong-looking pokemon to go up against the likes of Reshiram.
On the other hand...this really does feel like shameless pandering to me. I would much rather see them bring back a pokemon that would actually benefit from being in the new arc, the way Gomazou did in Battle Frontier, than to see a camera hog like Lizardon again. Fukamaru (who can evolve twice!) or one of his Jouto starters (who desperately need the screentime) may not be as much as a nostalgia trip as Lizardon it, but at least their inclusion wouldn't feel like just straight-up fanservice to me.