There is the hypothesis that the abnormal mitochondria could be in different proportion in different tissues, and that this percentage could change with age.

It is highly unlikely to happen, or to cause any clinical manifestations. Most of the flesh of the article is about ethics, being banned by the FDA, etc.

Let's call things by their name. Being worried about uncertainty is just a pretext here to try to enforce some religious values according to which a child can only have 2 parents of different sex.

Science is making such views obsolete. Many people hate that, so they try to use science as a pretext