The thing is the TRAs are relentless in trying to shut down conversation.
A while back they actually got advertisers to pull out of mumsnet, costing mumsnet a lot of money.
When the tide turns more I think Mumsnet will be more vocal. But the way modern society is is that the moment mumsnet gets labeled as transphobic or not doing enough to combat transphobia, it will get canceled, written off and shut down.
I think this is the only place that you can openly discuss these issues which does show that mumsnet are doing a lot more than other sites but they are a business after all and its a tightrope to not get written off as something that you aren't.
Just be patient.