Okay, so let’s go with Oxford and Meriam Webster who seem to agree. Censorship is the work of a censor. A censor an official who examines materials about to be published to determine if they have unacceptable content.
So, if you are arguing that this does not fit the dictionary definition of censorship then I agree entirely. There is no person who is a censor who is responsible for this, the materials were already published before they were blocked by law, and they were not even examined to see if they were unacceptable (which was a big part of the problem).
Great, we can look things up in the dictionary. Instead of trying to argue about definitions, though, perhaps you could explain why invoking the idea of “censorship” as a metaphor or in a contemporary understanding is unfair or inflammatory. After all, the definition of censorship does not include things like the government blocking access to any website that was created by their political opponents since they would have to find out the website was created by their opponent after the fact and they are censoring based on the author not based on the content.
If you honestly just don’t understand why someone would feel this is analogous to censorship, that’s fine. If you feel you understand why people would say that but you feel it is unwarranted, you could try to explain that. Simply flat out stating that it is inappropriate and referring back to word definitions doesn’t really illustrate any point other than that you have an inappropriate fixation with dictionaries.