It's very possible, tint does block most UV.
That tint looks awesome! I can't get over that you don't like it. I personally hate clear windows in everything. I mean, I really hate it, maybe more than you hate fake DRL headlights. I've seen some people get 35-50% tint and I'm even like, "what's the point?" Getting my Fleetwood tinted is the first thing I'd like to do to it. 35% is legal limit here, but I'm planning to take the risk on 20% like I did on the 94 convertible. I'd meant to take my 89 back to get the front windows done, but never got around to it. Probably should have, if it's indeed UV causing it, but it could very well be a combination of temperature and age as well. The dash vinyl, for some reason, has held up fine. I drove screws into it to un-warp it about 30-years ago, and it's stayed un-warped this whole time.
They do make clear tint just to block UV. I was thinking to have that done on the Fleetwood's windshield. It does have a slightly bluish color to it, though.
I don't think tint hurts the factory look. Lots of car ads portray them with tinted windows because it looks so much better.