Here's a quick test. Let's say Bob goes for a walk, but Bob's neighbor, John, is a complete dick and whenever Bob leaves his house to go for a walk, John follows him and just hurls non-stop insults at Bob.
Should John's behavior be illegal? You could argue that as long as he's not trespassing anywhere, and he has the right to free speech, then John should be legally allowed to do this. In that case, it makes no sense to make deadnaming a criminal offense. There's no discussion to be had, as we've decided that asshole-ish speech is not illegal.
If you say no, it's verbal harassment, and should be illegal, then you're saying free speech does have limits, and we just gotta decide if deadnaming is bad enough to be illegal.
So unless you follow someone around and harass them - just saying someone's so-called "deadname" shouldn't be illegal.
I worry that we've started to use the ponderous blunt government legal system more and more widely for things that used to be resolved via society and community censure. The law should be restricted to the most serious and large scale community disrupting acts, not for policing every bit of cheating, insults and lying. It's very unsuited for the latter.
100% agree. But since public shame and censure no longer work for limiting people's actions[1] that negatively affect others, what else do we have?
[1] And any time anyone tries, people scream "CANCEL CULTURE!!!!".
Which would also apply to places like pre-Musk Twitter, reddit, tumblr and Facebook (and indeed every social media site), all of which have lead to targeted and sustained harassment of people, often for things they didn't actually do.
Hurricane declining to accept KiwiFarms' /36 into its BGP table is community censure.
On a local scale, 'community censure' may work well. But not so much on a global scale, where a few determined activists on the other side of the world can get a person fired, take away their Internet services, or even have their banking services removed, all over issues of 'speech', with no due process involved.
Much like many other things. But, alas, we do not yet live in a world where people treat each other with even the simplest basic respect and we have to force the issue via laws.