the law itself stands until it is changed
I think that's right. But if the court says the law is incompatible with human rights legislation then the Scottish Government will have a stronger argument to delay further changing its policy.
It would also force the UK government to either to defend the EA2010 and appeal such a declaration, or commit to changing it. Either piss, or get off the pot, so to speak.
If you think about it it's a great wrecking move by the Scottish government.