Do you have any references or links or whatnot to support this? I thought css group was still big into testing. They're no longer called acid tests but I thought it was all still alive & well.
They are, they just don't use the Acid 1, 2, or 3 tests that you're familiar with. They currently use a manual test suite, which requires humans to look at reference output and compare it to what the rasterizer and compositor are doing.