Honestly Joker doesn't look that broken. He relies too much on a counter and both of his recoveries look pretty gimpable.
Oh, his grappling hook looks plenty gimpable. As an Ivysaur player, I'm telling you that Pikachu/Pichu mains are going to have a field day with him.
His winged recovery though? Yeah no. It goes farther then Inkling's and has invisibility. Have you tried to gimp an Inkling before? It ain't easy, and even if you do hit them they'll often still be able to recover if they aren't hit by a kill move.
It's too early to say if he's broken or not either way though, we'll have to wait and see.
But it's hard to guess, we'll have to see the damage and knockback on his moves. After all that's the only reason Peach and Wolf are so broken.
This undersells all the things that make those two so good. Wolf's amazing mobility, zoning, and range all play a part to how good he is, and I'd argue that they're even more important to him then just his raw power. Peach has an insane combo game which can be started off of a midrange projectile of all things, and while she may not be particularly fast her float does give her unique mobility options.