Last I checked, they had archive.is blacklisted; the people with power there had (as far as I can tell) come to the conclusion that people using that site to prove that websites had stated X on date Y were the bad guys. Of course, they still have archive.org sources everywhere, so the objection is not actually to archiving page content.
Tons of claims also seem to be sourced ultimately to thinly-disguised promotional material (e.g. claims of the prevalence of a problem backed up by the sites of companies offering products to combat the problem) and opinion pieces that happen to mention an objective (but not verified) claim in passing.