I love how Mike just casually ghosted all us early birds, didn't even release a statement or anything that the itch version is discontinued.
Unless of course he is cooking up steam keys or an update to make the itch version compatible COPIUM
The Steam version has integrated Steam support with the multiplayer, so even if multiplayer came to Itch, we'd be unable to play with other Steam players unless a server disjointed from Steam was added for both Itch and Steam players.
Of course, that won't happen because the dev has abandoned itch.io!