I feel like it is more of AI looking like the art style instead of the other way around. My only observation or "evidence" is how consistent the sprites are perfectly lining up with each other with the occasional human errors such as the neck at a different angle.
if AI were in use the sprites would be radically different, but the sprites show little to no change. The only way I can think of the art being this consistent but still AI is if human art was used beforehand to change the art style (ie. the current Studio Ghibli AI turning IRL images into the Ghibli style) or if a sprite were generated and then clothing articles were generated on top then edited (although I don't think that's possible without damaging the already generated sprite). But why go through all that work especially if the art was ready beforehand?
I honestly believe that all the art was drawn by a human, the change in style is most likely from constant refrenceing of the game mentioned (Metaphor: ReFantazio) as in Anselms full art I can see the creators original style peaking through. Anyway, this is my conclusion whether I'm right or wrong doesn't exactly matter to me I just wanted to share my own observations.