4A Games have confirmed in an official 10th anniversary update post today that Metro Exodus is still going to release for Linux and macOS as well.
They gave a small overview in the post about what's been going on like celebrating the first release of Metro 2033 which arrived back in March 2010. Not only that, they recently got acquired by Embracer Group who also control Koch Media, Saber Interactive, THQ Nordic and others. Specifically, 4A Games are now an independently run subsidiary of Saber Interactive.
For people waiting on official Linux support for Metro Exodus, there's good news. While it has been confirmed for a while now, they have been somewhat quiet on it. When mentioning about bringing it to the latest consoles with the Xbox Series X and the PlayStation 5 they also said this:
Aside from these enhanced versions for Gen 9, we recently brought Metro Exodus to more players through Amazon’s ‘Luna’ streaming service; and we’re also working on dedicated Linux* and Mac versions of the game. We’ll share more information about these closer to release.
Also confirmed is a new Metro game that is officially under development. They're not sharing anything on that, other than it being built for all modern tech as it's targeting PCs and the latest consoles. 4A also confirmed their commitment to "delivering a great story driven single player experience". On top of that, with Saber's help they're exploring a proper multiplayer Metro title but it's not clear if it will be part of the next Metro game or a title by itself.