I placed mr. game's image in spoiler. Also guys, mr. game is obviously foreign and doesn't speak the best english, so no bashing.
As for his idea. I have to disagree. Having taunt to do the transformation will only cause players to spam taunt in order to do the following things.
- respawn the power suit pieced at will.
- avoid getting hit during transformation.
- leaves you open after transformation.
The benefits of having the transformation as part of the Final Smash is that not only does it make the transformation something you gotta work for and rewarding. The Plasma blast attack she does prior to transformation gives Samus the space to transform without interruption.