I have never seen any fandom actually be able to coordinate decision-making about what is and is not part of that fandom, and I've been in the RPG industry in one way or another since the late 80s.
We won't even talk about the sci-fi/fantasy/speculative fiction/SF/high magic/low magic/steampunk/dieselpunk/you-name-it fandom communities, who all seem to spend about as much time trying to decide who to define out of the community as looking for things to be in it.
Not that I'm cynical. Never that.
Even worse? Someone (who didn't coin the term) is trying to trademark it.
https://litrpgforum.com/threads/stopping-the-litrpg-trademark.1667/
You know, to "protect" it from dangerous people. Scary stuff. That's one of the reasons I'm clinging to it - so Aleron Kong doesn't end up with final say on what is and isn't LitRPG. You wanna talk about cynical. ;)
Anyone that wants to do that deserves everything they get when they get exactly what they want. Which will ultimately be responsibility for maintaining and keeping up discussion around the term – which won't happen, because the be forced to defend the trademark lest it fall into legal limbo.
The worst thing that can happen is his own success.