That is what they should be informed of. If they have Googled genetically related problems and have not yet heard of PDG clinics, then Google Adsense has failed us miserably.
As for eugenics, the benefit of a society that knows how to squeeze the potential from people despite their problems far outweighs the benefit of a society that doesn't have those people to began with. But if a family is going to have X number of kids, then why not enable them to have the healthiest kids they can have? yes, PDG can have a cost in terms of genetic diversity, but I would rather put my money on the potential of genetic engineering then make people suffer on the slim chance that the genes for diabetes or breast cancer will mutate to that one genetic trait that will help us survive the next plague.