Saints Row 4 released a patch (to include the workshop only) for Windows only recently and broke cross OS multiplayer. We never hit "turn off automatic updates" because we didn't expect over a month of neglect.
I know Steam doesn't allow reverting explicitly, even though they have the old files available. It also forces updates upon you when launching the game unless in offline mode.
Is there a way to install the older version of Saints Row 4, get it to launch on Steam without updating, and play together?