They could do the same with Zoroark, Zangoose, ect. What makes Meowth in particular special above those two, excluding importance?
Absolutely nothing, but is that something to really even consider? Rosalina's moveset idea could have been implemented to Paper Mario and his partners, but perhaps Rosalina was a better choice as a brand new character. The fact is that Meowth IS such an important character.
I believe my newest one was...
B: Pay Day. Works as his appearance in Brawl; weak, but pushes opponents away.
B>: Thief. Meowth lunges forward, latches onto opponent, then hits them away. In the process of doing so, Meowth steals the opponents held item, including things like Link's bombs or Peach's vegetables.
B^: Fury Swipes. Meowth rapidly claws upward at the air in a combo scratch attack that carries opponents. Based on Meowth's attack animation from 3D Pokemon titles.
Bv: Dig. Meowth claws into the ground. On normal platforms, Meowth gains the ability to travel quickly and invulnerably underground for about 2 seconds, at the end in which he claws upward out of the ground. Releasing the button will cause Meowth to jump earlier. If Meowth digs too close to the edge of a platform, he will fall out. On thin platforms, Meowth simply falls through.
Final Smash: Hone Claws. Meowth's claws glow and grow 10x as long, increasing the range and power of his attacks. By rapidly slashing, Meowth can also create cyclones that shred and launch opponents. Based on powerful interpretations of Meowth's Fury Swipes in the anime.