EyeSight is new technology, very high-tech technology. Very few other manufacturers make camera based driver assist systems. EyeSight has special requirements for the windshield. Subarus with EyeSight get a different windshield from non-EyeSight Subarus.
Subaru does not bless non-Subaru windshields to be used with EyeSight. If you read your manual, you'll see that for most replacement parts, it "recommends" you use Subaru brand parts, or "advises against" using non-Subaru parts.
For windshield replacement on EyeSight models, it unambiguously states, "Do not install a front windshield other than a genuine SUBARU front windshield. The stereo cameras may not be able to detect objects accurately and the EyeSight system may not operate properly."
I would highly doubt that the problems that might be caused by using a non-spec windshield would render ACC and LKA totally unusable. More likely it would affect thresholds.
If you put non-spec brakes in you car, you might well be able to drive for two hours and stop successfully. That doesn't mean you haven't added 10% to your stopping distance. To then go on a public web site and announce that your non-spec brakes are safe based on such a faulty evaluation methodology would be rather irresponsible, I think.