Yes, the Simply Vinyl are definitely PVC. As stated upthread I think there are other factors and much of the nightmare stories have had less than appropriate environmental storage etc. I’ve had many of my most valuable albums in them, some for 40+ years, but I have no damp issues etc, and the vinyl is always in a poly or Nagaoka inner. Zero problems aside from the 7” singles I mentioned upthread that are in direct contact with the PVC. I do replace tired looking sleeves though, e.g. if they are yellowed or cracked, so maybe that saved me. I don’t have much in the way of Simply Vinyl, maybe three, but I’ve bought and sold a lot and I’ve never seen one with any issues, though again they do have poly inners.
I’d monitor rather than panic assuming you are using poly inners/Nags. Old 60s and 70s Decca poly inners are much more of a risk IMO, as are classical box sets (vinyl or CD) with foam inserts. Again there are threads on both somewhere. Record collections definitely do need checking and assessing now and again. Don’t assume nothing changes. I did a recent pass through when loading everything into Discogs and did a lot of cleaning, inner and outer sleeve swapping etc.