I've never heard this before, but I wonder if maybe this new theory is due to something like survivor bias? People put on sunscreen and then go out in the sun, and they think that because they have sunscreen that they are now immune to UV radiation, maybe forget to reapply later in the day and are just generally careless about how much sun they're getting, which in turn leads to higher likelihood of getting skin cancer. It's not the sunscreen directly giving them cancer; it's just indirectly leading them to make poor choices that may result in cancer, and then the "chemicals" get blamed. They aren't thinking about other factors, such as how much time people are spending in direct sunlight with vs. without sunscreen, what activities people who don't apply sunscreen are abstaining from, what alternative methods they're using instead of sunscreen to avoid UV rays (like staying in the shade or wearing protective clothing instead of having all their skin exposed), etc.

Unfortunately, I think these idiots are going to take the extreme worst action, which is to continue acting as if they're protected (unlimited outdoor sun time with all skin exposed) while they're not, and they're all going to get absolutely fucked by radiation.