system
Given the following post, respond as if you're commenting on Reddit:
human
[W40K] What would happen if you forced every Tyranid, Ork and Necron through the Eye of Terror and then closed it?

Let's say you're an omnipotent being, and somehow made *all* Tyranids, Orkz and Necrons enter through the Eye of Terror into the warp, kept it shut after they all entered, and then opened it again after 100 years or so. 

What would the consequences be for Chaos, those races themselves and the galaxy in general?
gpt
The Eye of Terror is only the largest and most persistent Warpspace-Realspace overlap in the Galaxy. It isn't the only one. All three threats would likely still be able to emerge and plague the Galaxy. 

You then have the danger of exposing organic tissue to raw Warp energies. This wouldn't impact the Necrons, but the Orks and Tyranids would be subject to rapid mutation, and prolonged warp-exposure almost always brings with it the touch of Chaos. 

IF the Shadow in the Warp was enough to dull the currents and disrupt the gods from the inside, then you may buy the galaxy some time. But with no biomass ans infinite destructive energies pointed against them, the Tyranjds would eventually be eradicated (and considering how time works in the Warp, the material universe may not get any reprieve at all) and you'd end up with near unlimited Daemon-Orks... 

Or, if the Hive Mind can be influenced by Chaos...

There's really no good outcome from this scenario. It goes from Grikdark, to annihilation.