Turns out most Grab Releases don't work on humans!

[Thinkaman]

KO Punch still does, as well as the faster-but-weaker-and-lower ZSS and Shulk up-b custom moves. Those are the only ones!

Full research topic:
http://smashboards.com/threads/grab-release-mega-thread-spoilers-almost-zero-combos.373720/

 

[Goodstyle_4]

Wow, thanks a lot man. That really makes me feel better about the whole thing, we really just gotta worry about Mac, Zamus and Shulk.

And Rosalina's grab release Usmash and Uair don't work either? This is huge since that match up is annoying.

 

[Thinkaman]

Correct, nothing else works. You can jump well above Rosalina. Luma shouldn't matter, since it's an issue of vertical distance.

To be clear, ZSS and Shulk both get it only on one non-default up-b with less kill power and vertical distance. Even with the grab release, it remains to be seen if they would take it in this matchup.

The scare of Little Mac's KO Punch out of grab is also really easy to exaggerate. KO Punch is unblockable, so any time Little Mac grabs an opponent, he could have just KO Punched them in the first place!

The only difference is, he can whiff a grab and still have KO Punch ready... if he isn't punished. If Wario does any meaningful punish to Little Mac, the KO Punch is gone anyway. Ultimately, this trick shouldn't really change the matchup much.