Borderlands 3 will release at the autumn 2019, and many people are wondering if it will have support for Linux distros? The short answer is that it's highly unlikely that it will support Linux at launch, since the PC version of the game is tied exclusively to Epic Games Store. This game store does not support Linux at all, so Linux users won't even be able to install the launcher for the game. This in turn makes it seem highly unlikely that Borderlands 3 will have support for Linux.
On April 1st 2020 Borderlands 3 will release for other PC stores such as Steam, so if it will ever get Linux support, this is probably the time it will get it. However, we have to wait a bit before we find out.