The legal case is a political initiative, it seems to me.
The GRA 2004 is explicit that, where a parent transitions after becoming a parent and obtains a GRC, no child of that parent's Birth Certificate can be changed. That is, if it is the Father who transitions, the father cannot change his status to Mother and vice versa.
This case is about where the parent transitions and obtains a GRC before becoming a parent.
This raises the question of the validity of the granting of the GRC.
It also raises the question of whose needs are paramount here: is it that of the child needing to know who is its Mother; or is it the needs of the adult who obtained a GRC to achieve legal male status?
[Personally, I would like to see the GRC rescinded in this case, since it was obtained in breach of the current requirements [see 2.1a and 2.1c]:
2 Determination of applications
(1) In the case of an application under section 1(1)(a), the Panel must grant the application if satisfied that the applicant—
(a) has or has had gender dysphoria,
(b) has lived in the acquired gender throughout the period of two years ending with the date on which the application is made,
(c) intends to continue to live in the acquired gender until death, and
(d) complies with the requirements imposed by and under section 3.
www.legislation.gov.uk/ukpga/2004/7/section/2