Generally, no, this is not the case. The few AAA developed games that come to Linux are generally ported by third party groups. One of the most recent AAA games to get a release on Linux is Rise of the Tomb Raider, which was ported by Feral Interactive. Big publishers generally aren’t too interested in making a Linux port available, so smaller port houses like Feral and Aspyr pick up the tab for the publishers. The PC port of Rise of the Tomb Raider was released in 2016.
Bioshock Infinite was ported by Virtual Programming, and isn’t a completely native port. Virtual Programming has been working on ARMA III for Linux currently.
Right now, it’s just individuals like Ryan Gordon and others, as well as port groups listed above who are still responsible for making most of those ports happen. Though indie developers and b-tier developers have been doing Linux ports themselves when they can.
That is not entirely true. Valve does have that Artifact card game getting a release later this year:
And it will have a simultaneous Windows/ Linux and Mac release this November. What’s funny is that the game is using Source 2.