When people bring up posts like this they never say what the "heresies" are. People aren't getting "cancelled" for their takes on taxes. People aren't getting fired for picking nomad over kubernetes. People are getting called out for denying the existence of people who aren't like them. When someone gets fired for, as an example, purposefully misgendering their colleagues- that isn't getting fired for having a bad opinion, that's being fired for making a hostile work environment.
What's always interesting to me is that these "free speech absolutists" are explicitly calling out the left here, when the right is the one passing "don't say gay" legislation and refusing to allow trans children the healthcare needed to save their lives. The right is also kicking everyone out of their party who doesn't bow before Trump. To say that the left is creating heresies while ignoring that the right is literally creating new dogma is just delusional to me.