Only just a few minutes ago, I thought everything was fine on the MAC side. Up until a few weeks ago, I was on a much older version of MAC OS, which still updated and ran the game properly. Only recently did I update to Catalina.
To make a long story short, Steam does not want to automatically update the game on MAC anymore and there isn't anything I can do to change that. Even though the only available build for MAC is 4.1, my test PC is still locked at 4.0.2, which is likely the last version I exported specifically for MAC OS. It's probable that this issue has been going on all along - I'm only just noticing now since I have very recently updated my OS. Either way, since I can't test or force downloads moving forward for MAC, MAC OS support is officially terminated effective immediately and permanently.
Please note that the game still functions on whatever the most recent build you were able to download is and still functions via Bootcamp and other Windows emulating programs for current updates. I'm very sorry it ended up like this, especially since I was so excited to re-add that functionality to the Steam Store information.
While this is a sad development, I was not able to make DLC for MAC moving forward regardless, so it's likely that MAC OS's were doomed to fall behind eventually. It's just sad that today is that day.
In just a few minutes, MAC OS support will be removed from the CoA Steam Store.
I hope for better news in the next update.
//hardytier