Huh, not sure what this means.
I have AMD Radeon R9 M370X, with this going open-source means can change more settings for that?
AMD says it will be publishing documentation for MES around the end of May, and will then release the source code some time afterward.
I don’t know too, for me it sounds like HAGS and multiGPU at the same time, something that manages the queues or … whatever, I don’t know, but I really love AMDs opensource approach in general! 
This simply to an extent makes for a stronger win for Opensource like Linux
A key benefit is Amd can merge code from the world wide community. Meaning potentially quicker improvements to the code base. Things with the specification of MES and source code means even stronger Linux support for open drivers vs using strict proprietary drivers
Quite sometime ago And improved overall support with the core Kernel driver to work along side either closed driver and the open driver.
The micro code is likely tied to say the GPU bios(firmware). Some updates on other components are independent of the OS but hardware code that improves the card’s bios
This s can for example also help gaming consoles as they can monitor GitHub for attractive code changes that can help reduce R&D on their end to improve the micro code that may for example reduce improve micro stuttering and screen tarung at a guess.
Nvidia 10series cards had a firmware bios update that added part DP 1.4 support for example but due to hardware limiting factors could not use the full do 1.4 spec like DSC that came in the 29series cards