The private company is a publisher which is being held responsible for what it chooses to publish. Individual citizens have a right to hold and express their views, but not an automatic right to publication. If their views are so odious as to invite criminal sanction, it's entirely reasonable for them to incur extra costs/difficulty of publication.

Now this is where someone usually pipes up with 'but my freedoms!' and that's all very well, but if the freedom they wish to exercise involves proposing limits on the freedom of others (perhaps even by ending their lives) then that person is proposing a zero-sum view of freedom for others and cannot complain about having a zero-sum calculus imposed upon their own political expression.

Popper's paradox of tolerance may be explicable in terms of the boundary between positive and zero-sum games. https://en.wikipedia.org/wiki/Paradox_of_tolerance