Feral Interactive [Official Site] have now confirmed that Total War Saga: Thrones of Britannia will arrive on Linux next month, with the Mac release this month. While the game released for Windows at the start of this month.
We're used to delays by now on Linux, thankfully ~2 months isn't really all that long to wait.
They sent this tweet out just now:
Linux generals! THRONES OF BRITANNIA, the first in the new Total War Saga series, is coming to Linux in June.— Feral Interactive (@feralgames) May 22, 2018
System requirements will be announced shortly. In the meantime, prepare for your campaign of conquest on the minisite: https://t.co/zFVPI5Gkns pic.twitter.com/GuAv52OmeE
Thrones has been a bit of a divisive game for the Total War franchise, with firmly "Mixed" user reviews on Steam. The development team has acknowledged this in a recent blog post detailing what they're going to do to improve the game. They already released a beta patch for this, so hopefully it will turn things around.