I think as others have said the real problem is the GRA.
No other act was allowed to underming the purpose and intent of the EA.
And in doing that the law was used by Labour, and all those who nodded it through, to effectively make what is little more than social engineering, a legal obligation on society.
I think this is where even if the Court says yes, clarify that sex in the EA is about biology, there would then be any number of amendments, just like the SSE but the other way round to say all the way that TW with a GRC must be taken as though they were biologically female.
In other words, undermine the court decision.
Although to be positive, maybe it would be the first step to repealing the GRA!