This employee is an idiot and they deserved to be fired.

Shouting down others is not speech - it’s censorship, even a company with broad internal speech protections/policy is likely to enforce discourse standards.

Google would be better off taking a hard stance here - their culture from the outside seems pretty messed up, they’re going to need to fire a lot more to fix it (starting with their CEO imo).

This is independent of the specific views the employee held, though I think those views in this case are also wrong and the company can (and arguably should) fire people who hold views in conflict with the mission, especially when they act to cause problems internally.