I recently submitted "Storybook Brawl" to the site and it was rejected. I was half expecting this to happen since it's still in early access but the reason given was "We are not accepting endless games with arbitrary goals"

Given that the game is very similar to any of the hearthstone solo player missions which are all on the site already I am incredibly confused. The proposed catagory was for "vs ai" and it definitely has an ending point.

I'm posting up to see if there's anyway I can follow up on this rejection as simply I don't feel the reasons given make sense.

hearthstone was probably added before the game requests got stricter

Yes, if you think you have more information that could help the game to be approved, you can resubmit with that additional info.