Pretty much, I went on his blog just to see around about when the "chibi art rework" started, and whilst it did happen around the time he started work on godot, he 100% wasn't saying "this game is a spin-off whilst I just learn godot" and every change was intended for the main game.
This was toward the end of 2017, so he has been learning it for years. Back then people were complaining about the new art, saying how "child-like" it looked, which 100% was true, it wasn't good, at all. I assume he must have went "oh fuck people are actually not liking this and are leaving, they're gonna hate the main game, let me go "haha haha this is just for the spin-off whilst I learn, totally!" to appease people"
The amount of time the game has taken, even with the engine switch, coupled with his either shitty or brush-off attitude (can't remember which one, maybe both, brush-off 100% though) this game can get f'd in my honest opinion.