Only if that rule is accurately defined. It's definitely not occuring in the link provided unless you consider "getting bullied and disagreeing with other user" transphobia.
I'm not going to engage with the other user anymore. They want freedom to insult and censor because "they're righteous". It's not an attitude that's specific to one group, mind you, but it's definitely an enlightening interaction in the context of this thread.
Authortiarianism doesn't sit well with me and I consider it an absolute no but I'm playing by the instance rules. I don't think they are but it is what it is.
We'll see how this space develops. Individual users are not relevant, anyway, but the aggregate.
I don't particular want to engage too much on this but I guess if you think the user was being nice then you have a very inconsistent view.
My take, looking at the reactions, is that it's less so a safe space and more a place to bully dissent if you have a specific righteous attitude.
And we can look at the user's specific interactions in the Reddit link they provided or with me. Calling generic "transphobia" doesn't cut it.
If after looking at that you're 100% in agreement of their actions then revising your rules to be more honest will avoid similar conversations or encounters.