FF7R won't be Playstation exclusive (maybe timed, who knows), so if the NX is up to the task, a port wouldn't be out of the cards, and I pointed out a page ago or so that in the same Nintendo Direct they were promoting FF Explorers, which Cloud is a cameo/summon in.
People forget that Smash is an amazing place for Nintendo to drive interest and cross-promote. Nintendo has a predominantly younger audience, they see these characters and they become legendary to them. Kids will want to play FF7R on their Wii U with their Cloud Amiibo while using it to unlock something in their FF Explorers game.
They don't only add characters because of cross promotion otherwise R.O.B. and Mr. Game and Watch wouldn't be a thing, but it's certainly a consideration, and moreso for DLC characters. DLC is added revenue, the basic roster is the basic roster and sometimes just needs warm bodies to fill it out. You leave out the best ones so people throw their wallets at you after they already bought the game.
Oh, left out my point. Unless there are new Banjo games on the horizon, cross promotion of Banjo-Kazooie makes less sense than Cloud.