Odd, reading on the Alien Isolation forums about anti aliasing it some of the posters mention SMAA T2X which supposedly gets rid of some of the shimmering. Perhaps AMD only?
You could try forcing AA using the AMD/Nvidia control panel, not tried it myself because i'm downsampling from 4K and not using AA to keep the FPS up.
Here are the options for Nvidia, you can set the settings for just Alien Isolation if you use the program settings tab, this will set it for all games.
In the benchmark output I noticed that "Multithreaded Shadow Rending=Off". It's particular edges with shadows that's screwed, all other edges and surfaces look good.
Turned off "ChromaticAberrations" because to my eyes it's abhorrent.
The Nvidia control panel does nothing at all unfortunately. Even tried 32x CSAA and SLI 64x CSAA and nada. Thankfully the benchmark mode makes testing quick.
I think I'll try downsampling but I've read that it doesn't help that much either.
i have a 7870 and its stuck at t1x and it also was on the 7850 "although that was no supprize"
i wonder why now. i just assumed it was nvidia special feature. but if you have 780's and cant enable it either...
-edit-
leaving this here as a warning to all with greasy fingers.. (my finger slipped)