If I had to guess, I'd say you've never played TP. Thing is, TP
was different, and if this isn't the old OoT Link, there's something afoot. It's been OoT Link since SSB's creation, up until now, which definitely says something.
I really only worry about it at all because Wolf Link would rawk.
lol but perhaps you don't know the lore?
Link in TP is a reincarnation of every other Link ever; basically it's the same Link in essence every time. He's got the same humble personality, and he's got an upgraded body to boot. He's still Link no matter how you look at it, and if you're going argue that you're pretty clueless.
TP is the recent representation that they chose to go with, to keep with the times, but I don't think they'd totally shaft characters like Shiek simply because of newer games. If you look at the TP Link in Brawl his hair color is more blonde than the actual TP Link. A shout out to OoT Link?
Another thing is that it's been the OoT link for the others because there
was no other Link at the time. Young Link was making his scene with games like Majora's mask, the hendheld titles, and even Wind Waker Link is a branch off of him. They included yong Link in Melee, but they still didn't get rid of OoT Link.
And honestly? There isn't much difference between OoT Zelda and TP Zelda. They're still the same core-characters. They simply have subtle asthetic make-overs. It really isn't out of the question for Zelda to keep the Shiek transformation.
If I were Sakurai, I really wouldn't want to complicate things anyway.