I'm getting the feeling the word censor in #bitcoin is loosing its meaning everyday. Everyone throwing the word around lately.
IMO, thinking about censorship is when the majority chooses to prevent or allow a specific action/activity. The keyword is the majority.
My take on this is simple. An individual pool can choose the kinds of transactions to accept as long as the transactions are not a majority of what pools already reject.
A majority of the pools ideally should not prevent a specific kind of transaction. That would as censorship in my book.