[shmerl]

I'm not a backer, but I tried to find out about their Linux plans. Linux support was their reached stretch goal, so they should fulfill it. But no one says anything definitive. The last thing I've heard, Chris Roberts mentioned something that they'll make it after the initial release.

They planned to use Vulkan in the engine in general, but it seems that Lumberyard doesn't even support it yet (and Linux is only listed as an upcoming supported OS in Lumberyard FAQ).