I feel like it is still censorship, but a degree of censorship required for public safety is tolerable...
Unless he's saying that social media sites policing content on their platform isn't censorship, because it's not. It's only censorship if it's a government doing it, you have the right to control what is said on a platform you own
It's far from my only understanding of it, it's just the first thing that comes to mind for what might make him averse to a list of "others" being created
He probably would have also seen what happened with the US's registry of Japanese people, which didn't go great for them either
Random bit of
sheetmetal