The Custom Moveset Debate?
Are they discussing if they'll allow custom movesets at tournaments?
Originally he was discussing some of the problems with early tournaments with custom moves. Like how people who don't have them all unlocked are at a disadvantage because they can't lab it out against the custom moves they don't have.
Like, say you're introduced to Falco's laser ball mid-tournament and you didn't know he had that move (because you haven't unlocked it yet and there isn't a complete list of custom moves yet per character). You can try to adapt to it mid-match and everything but it's not working out. So, after the set you decide you want to lab it out on how to beat the laser ball -- you know, see if you have any options against it.
...Except you realize you haven't unlocked it yet so now you can't learn about it until you do. Now think about multiplying that by every character and every custom move in the game that you'd have to learn + how those custom moves interact with each other + how Palutena/Miis having the advantage of having theirs unlocked from the start. Palutena would have an adv. early on in a sense.
He wasn't having a discussion that would actually end in custom moves being banned, just a harmless discussion about some of the problems that have arisen with how you have to unlock them and the problems the community faces with new players entering the scene and not having everything unlocked, how unfair it could be, etc etc. At least, for the 3DS version as it stands right now early on in the game's life.
Wii U version would be a different story because it would be possible to transfer the moves to Wii Us so all you need is one 3DS game that has all the moves to transfer them to every Wii U save file in the venue. 3DS players themselves have to unlock them per their 3DS though...
It makes me kinda wish there was a way to streetpass or 'trade' custom moves. :/