User blog comment:DBFan9000/Ash-Greninja in Super Smash Bros. Ultimate?!/@comment-25956022-20181023170316

By "Transformational Final Smashes", they mean all Final Smashes which transforms the character with a different moveset, not just cosmetic.

In Ultimate, Little Mac transforms into Giga Mac, King Dedede into Masked Dedede, and Zero Suit Samus into Samus, but they all just do cinematic attacks (ZS Samus' FS can be controlled a bit, but it doesn't mean she got a different moveset at that time).