The problem is potentially real because, as you see intuitively, these beings would not be seen as normal when given a full autopsy should they be killed in some way and require forensic analysis. This is a risk the Extraterrestrial Alliance is willing to make because they are, in effect, pulling out all the stops, so to speak, to counter the Shift in Consciousness and maintain the upper hand in controlling the fate of humans. They are willing to take the risk as well because they have many operatives who can intercede and to cause manipulation of circumstances, including the physical being to be examined, as well as how people act, what they do with the information they obtain, and so forth, because of the ability of mind control to manipulate people and limit their actions and awareness. So there are ways to suppress anything unusual that comes up, much in the way they will do with unusual alien encounters and UFO sightings. Keep in mind that being able to move through dimensions and to alter time to move back and forth, they have the ability to prevent such examinations from happening by causing the disappearance of the being in question, so it is not available to be examined. So there are various means in which they can stay on top of this.
The other aspect here is that we are talking about a relatively short time window from this point going forward. Within a 10-year period, the expectation is there will be a final solution in place for humanity. So the young being born now will remain fully functional and have no problems far beyond this time window. The only awkward situation would be in the case of an accidental death, so that combination of characteristics and situational remedies will allow this to go forward aggressively with little risk to the Extraterrestrial Alliance of being discovered in time to make a difference.