Mark Z recently announced that FB is banning holocaust denial going forward. (While there are trade-offs involved here, I support the decision in the current environment)
I think there are lots of intelligent, rational people that have widely divergent opinions on how to balance free expression with the requirements of living in an educated, civil society.... and anyone who thinks establishing the correct balance is a "no brainer" has demonstrated that they haven't thought about it very hard.
While I am generally in support of tamping down in the spread of anti-Semitism and white-nationalism, I fully expect an algorithmic ban on "Holocaust denial" to turn into a partial de-facto ban on discussing the Holocaust and discussing holocaust deniers. (There is also much to be said that the appropriate remedy for bad speech is more speech)
Please, whatever you do.... painting Mr. Z's position itself as "holocaust denial" is just scummy.
And anyone who thinks there is a clear-line (decidable by an algorithm no less!) that enables one to distinguish between Holocaust denial and simply discussing the holocaust... has never tried to write such an algorithm.