While I think Lun is talking shit in pretty much all of her posts, this seems... untrue?
After re-checking, it turns out I misremembered about Rain and Ermac, who were unique from their first appearance. Sorry about that!
However, there were indeed 4 characters with completely redesigned movelists:
Reptile in MK1 had no unique moves, just Scorpion + Sub-Zero's moves.
Noob in MK2 just had Scorp's moves. In MK3, he had no specials at all.
Smoke in MK2 just had Scorp's moves. In MK3, same thing. In UMK3, he's a mix of Scorpion + Ermac.
Jade in MK2 just had Kitana's moves.