Every antivaxer knows the Science shows vaccines work
Having debated a couple who are quite intelligent otherwise, I'm going to have to dispute that.
Sure, they know broadly that exposing the immune system to something that looks like a pathogen primes it to respond to that pathogen in the future, but they tend to be way off on the implications. I've heard it suggested that too many vaccines cause people to run out of immune memory. I've heard that all antibodies cause inflammation. I've heard that previous attempts to produce coronavirus vaccines killed the majority of test subjects years later.
None of those claims are true, and the only way they could be true is if everyone in the field of immunology is lying all the time.
In the context of ad-supported algorithmic social media, offensive is the wrong question. It's about brand damage.
Showing an ad next to something that actually offends people can damage a brand, but even something a little edgy might turn off customers of a brand with a more formal or conservative audience. The algorithm's ultimate goal is to get people to watch ads, so something a little edgy might reduce the reach of that content. Censoring it prevents the algorithmic downrank.