That flashback sequence Wash had in Season 12 when he got knocked out by Locus seems weirdly similar to the experience Locus just had in the Gateway.
I think it’s likely Wash got to Doctor Grey for treatment via teleport cube, especially with the way he almost died…and we know now that the energy the Gateway uses is very similar to that used by the teleport cubes.
What if the teleport cubes have been briefly passing people through the Gateway’s “testing ground” space, the way that the jungle temple pops people in and back out? But those using the cubes are only affected by the brief encounter with the testing ground if they’re unconscious.
Or maybe if they get zapped “in”…and never get zapped back “out.”
I think that #bringbackdoc2k15 is going to find its resolution as soon as someone gets through the Gateway.