Yes @alphapie, I said we can't know from the information given if they're disappointed, but going through all that effort for a boy raises concerns for me, not because it's surrogacy.
With the non-bio parent adopting the child, there would hopefully be the appropriate checks in place though the US has had some recent high profile cases showing some states' adoption checks are not as strong as many would desire. Any investigation into their parenting and the girl's safety would be separate from this legal case which has sadly been widely publicised which raises concerns about the girl finding it later either way, but general thoughts is that I hope there have been appropriate checks and care.
As for your imaginary cases, again, suing the company makes sense though they have to balance that with their kids knowing. With the first situation with triplets, they're all equally in the same boat so less of an issue though hopefully additional support could also be obtained. With the disability one, that has the same concerns and yes, it would be great if there were checks and preferably support and care. I'm not pro-removal in any of the cases, I'm pro-recognizing a higher risk situation and making additional checks and having support in place, even knowing our systems - and even less the systems of the US - are built for that.
To those who have the same view on straight couples who suffer gender disappointment, fair play, you're an equal opportunity numpty.
Sex disappointment is a wide field. The parent who has a momentary emotion and works through it is not the same as the one who spends months ruminating over it. We know the latter is more likely to be violent, we have plenty of cases and examples on this.
Trying to make all that disappointment the same is bullshit. We can recognize emotions happen and the risks of a parent having on-going issues with a child's sex, even if we can't 100% tell if this specific couple has on-going issues.
Also, is a straight couple one with two straight people or are you using that to mean a mixed sex couple? Mixed sex couples don't have to involve straight people.