| Pavolink said: You can unlock majority of the costumes in SMM without amiibo. So it is false the without amiibo that content would have not been in the game. |
Except Takashi Tezuka himself said that the costumes from different franchises were an idea they implemented when they were looking for something to add to amiibo, those costumes were going to be exclusive to the toy until few months before the release, but at the end they decided to have it unlocked because they though most fans would love them.
The exact opposite of what you said 
So amiibo was actually the reason why those costumes from other games exist even when they are not locked at the end. Worst thing of the generation.







