crustychristmastree
I'm not a legal bod, but as I understand it, there are two parts to this. The equality act and the gender recognition act.
The gender recognition act gives someone the legal status woman.
Your screenshot is referring to the equality act.
Which means, that you cannot be discriminated against if you are thinking of transitioning. Which could be telling your best mate.
It doesn't give you the legal status women. But it is nonetheless a protected characteristic.
As is your sex. Which is where the conflict arises.
Feminists have been trying to keep the gender recognition act as something that requires stiff criteria, largely to stop men being transferred to women's prison. Because that is about the only arena in which you have to have a gender recognition certificate.
In terms of the equality act, you are quite right in that it mimics self ID, on the basis of 'even thinking about transitioning is a protected characteristic'.
I think The Labour Party using self ID, are not referring to the gender recognition act version of self ID, ie they won't be legally women. They are referring to the protected characteristic.
I think.