From what I can read, the dev himself removed the game because of "stress". Steam has previously removed the game for copyright reasons, but readmitted it afterward.

The stress was due to the huge popularity the game got thanks to YouTube and Twitch.

Rejecting is different than removing.

I don't know what the problem is between the Steam Store and itch, but your Google search confirmed what I just said: Steam never removed a game just because; they removed games that break copyright rules or their TOS.