I don't think it doesn't sound Pokemon like, though? I do wonder what this theme could possibly be used for. He said it wasn't a "main Pokemon theme" so we know it's not a rival battle theme or anything like that.
It certainly sounds like something from Undertale or Deltarune. Not particularly fond of the song quite yet, but I'm happy for him. To compose music for Game Freak on a main series Pokémon title is arguably bigger than his Little Town Hero compositions. I might grow into the song after hearing it a bit more, wherever it pops up in the game.