It makes sense for them though. It doesn't matter if one plays the right side or the devils advocate, if they forces decision to be made.
They would, quite frankly, love it if Colorado declared unborn fetuses to be persons, and wrongfull death fee would be cheap compared to the campaign they've been pushing for decades.
But if not, then they're going to demonstrate to people the consequences of non personhood for fetuses.
Chances are good even if they win, it will spur legislation that gives fetuses more rights, which is still a good thing.
So all in all, this appears to fit in line with their primary mission.