For those of you that use Mesa drivers, myself included, the developers have been working hard at this driver package. Mesa 18.2.1 is a bug fix version. It seems to me from reading the comments from their website that this version fixes some of the tessellation problems found in Batman: Arkham Nights. This fix is mostly related to DXVK which converts Direct X to Vulkan. Steam uses this in their new SteamPlay using the Proton project.
For Vulkan, they updated the XML and headers to version 1.1.84. Which added a new module for Ray tracing. This is good news for people who own or will be owning the new RTX cards from Nvidia. There are several Nvidia contributors that made this possible.
However, I did not see much for Radeon cards in this version. I do use a Radeon cards but I use the AMD Pro driver which is an overlay to Mesa.
On Ubuntu 18.04, I use the Ubuntu-X team updated Mesa drivers. However after checking the version, it is on Mesa 18.1.5. So my system is a little behind. I do have to stay on this version to keep the AMD Pro drivers. Until AMD updates their driver, I am stuck with this older version.
Conclusion is that unless you are using a RTX card from Nvidia, there is no need to update to this new version. Especially if everything is working for you with the version of Mesa driver that you have installed on your Linux box. Except if you play alot of Batman and need the tessellation fixed that this version offers you. I like to hear your comments about this version. Please leave them below.