I don't see a pengiun on the game page, and for a Paradox published game this is a rarity...
I suspect there will still be a Linux version. I recall Eugen didn't initially have it with ALB an RD either, but it was introduced a bit later. The base engine itself has already been used in Linux and since Steel Division is based on it I suspect it will be no different case.
No plans for the game to be released on either [GNU/Linux or macOS] for the moment but, as with all things, that may change.