"Oh no, people are complaining about me going back to correct something 0.001% of players would've noticed instead of a consistently awful looking part of my popular game that I can easily fix going forward! Well nuts to them, they'll just ask for more fixes! What's next, fixing the grammar on some of the translations?"
Come on man. It shouldn't matter if someone pointing out this mistake is being snarky or not, it's a legitimate issue that he's ignoring by sticking his fingers in his ears and going LALALALALALA. If he fixed the teeth starting with Episode 11, I would not expect him to halt production on future episodes just to go back to 1-10 and fix those first. Some people might ask for that, but that actually is unreasonable.
Now, when the game is complete, could he go back to fix past mistakes in a simple patch? Sure. Would he? I think he'd only do it as part of a massive remaster project, but his idea for a new game might take precedent.