Yes you're right that Tom Nook would fill in a representation role for AC since that series sells like digital hot cakes. Though we're not Sakurai, can we ourselves see Nook with a moveset and playstyle that fits into Smash - preferably not a clone of Villager? Sakurai has gone out of his way to differentiate similar characters, it seems to be, looking at Mario and Luigi with his flutter jump.
Lucario was indeed insanely marketable and appeared in Brawl while Diamond and Pearl were huge. But with Black and White, Lucario was effectively replaced by Zoroark, who was admittedly used less than Lucario. With X & Y, it really seemed that Mewtwo filled in that role after Zoroark. If you have a good recent example, I'm curious to know it, but Lucario hasn't been marketed in that same vein since. He did come up with Zoroark and Mewtwo as Rumble U figurines, but that's about it. He does fill in an important gameplay niche, I'll give you that.
Wolf Link would be very surprising and would bring a really interesting playstyle to the roster, but I personally think that with more Zelda characters in, the series runs the risk of over-representation, especially since it's a third Link. The same over-representation issue can be argued with Female Pokemon Trainer.
If lots of people, like you have, have also forgotten about Lucas, I can only wonder if Sakurai feels the same way or has noticed it and what that would mean for the poor little guy. =p
Wolf, I would argue, is necessary. He fills an important villain role in the roster. He, along with Fox and Falco, have big issues with similar movesets. But to touch Fox or Falco would be sacrilege to many people, so it makes sense why Wolf would then have the finger pointed at him, being the newcomer.
I'm enjoying this convo, by the way ^^
