Oh no, we are going through the period(lol) where people overrate certain customs due to intense hype that they're legal.
Later down the line they'll get Lucario'd.
Greninja'd = nerfed
Lucario'd = tough when the meta was fresh out the womb, but later becomes a complete joke to some players.
I can see Shulks customs actually being hella good because people are so vocal about Ike(his rival it seems since he and Shulk are the 2 best swordsman archetypes in Sm4sh) being a complete monster with his customs. The ones that are rarely mentioned tend to be stupidly good later down the line like Pac-man,Shulk,Marth,Greninja,Fox,Ness.
Hope it becomes legal at the tournaments i go to. I always ask for custom matches to see how MK does against them but they say "i haven't unlocked them".