FWIW, that thread seems to be pretty confused about what, if anything, Vulkan could do for the problem of "my hardware is too old for the March 11, 2010 version of OpenGL to be available." Which is, at heart, "nothing specific to Vulkan in any way", since the same solution in Vulkan could equally apply in OpenGL.
There is definitely nothing wrong with Vulkan, but it isn't a magic pixie-dust that'll improve anything automatically either. It may
allow Wube to do things they couldn't before it rolled out, but that takes work, and isn't free.
Same thing as DirectX 12 where an API that could be used by the highest end engines to remove a bottleneck, with substantial work, seemed to give people the impression that it was some sort of "turn on DirectX 12, moar framez" don't suck button the developers were refusing to press.
For all practical purposes Vulkan support ... probably mostly means more graphics driver bugs, but otherwise, not all that much day to day. In fact, the most likely initial state would be that Factorio has Vulkan support and looks literally identical, because it is literally identical: same graphics, different API putting them on the screen identically.
So, yeah, I don't think that thread is particularly relevant to the question the OP asked. Doesn't seem like Factorio has a performance bottleneck on in-driver or in-API locking at this time (though, of course, that could be an issue Wube face), and so even with a dramatic rewrite to the new less-lock-contention API it wouldn't be likely to change much.
