That these transphobic moral panics in the press are *always* this simple to debunk tells you a lot about the level of good faith their advocates operate under. https://twitter.com/NotRightRuth/status/1359453509003980803
They mean to provoke such a strong emotional response (in this case, "the trans won't let you say 'mother' anymore!") that even when it's trivially shown to be a load of nonsense, the emotional response lingers and the angry defensiveness overrides any attempt at debunking.
This press approach makes it feel personal, that the Other - in this case, trans people - is coming specifically for them, to ruin their lives, and so defensive hostility takes over, reinforced by other people left feeling the same way, and then the hate echo chamber never stops.
And when you're primed to believe that trans people are trying to change everything and take everything away from you, another story like this comes along and you don't look at facts, you just respond "well of course the trans are doing that, they're scum" and the anger continues
If you ever look at the feed of a committed transphobe on here, it's a near constant sharing of scare stories and wild suppositions and treating any kind of defensiveness from anyone trans as an unprovoked hostile violent attack on them. It's a perpetual anger machine.
So coming back to the original tweet, coming up to someone like that, they won't engage, because they are marinated in suspicion, rage, fear, and a hatred-they-feel-is-justified. That's why it doesn't matter that it's easy to debunk. And the ones writing the hit pieces know this.