He won't say it any further down in the essay, but the free inquiry that he's whining about losing is the "inquiry" into whether people who are different than you deserve humanity or not.
That seems pretty presumptuous. How are you certain that is what he is saying?
You can get canceled for vaccines, climate change, masks, covid numbers, trump, homeless problems, not being a true vegan or the act of throwing dog shit in other peoples trash cans. So absolutely. Actually I thought his 4 quadrants argument was weak and everything up till that line you pointed at was uninsightful.
Something that I don't really care for about this particular style of discourse is that, fundamentally, it's a lot of words in defense of a somewhat milquetoast idea. Paul clearly feels like this point needs a solid defense. While I can imagine people who'd disagree with the general principle he's arguing for, it's not all that controversial. Paul was clearly thinking of something when he wrote this, as he felt it timely and worthy of defense, but it's not clear what. It'd engender a lot more interesting discussion were he to discuss some concrete examples, as then we could talk more about whether the principle here fits the situations he has in mind. Two people might agree that being helplessly addicted to drugs, but one could be thinking of harsh sentencing and three strikes laws for drug dealers and the other could be thinking of taxpayer-funded rehab programs. It's a fine general principle, but the social outcomes of the specific implementations of it are vastly different, and therein lies some interesting discussion that's denied by speaking in general terms.