I actually think it would be more interesting if it turns out that reversing biotransference isn't possible - but resurrecting the necron species with a fixed genome is. That way you'd split up the necrons into two camps (one willing to work for a better future for their "children" rather than for themselves, the other not caring as it is not in their own self-interest to do so), possibly even a full blown schism instead of the muted bickering between the various dynasties, which would add an interesting dynamic to the fic to explore.
Also the thought of a necron of all things experiencing parenthood is funny.
Plus you can have moments like this:
There was chaos among the ranks of living metal. Multitudes of Necron Lords, Overlords, even Phaerons exchanged sharp words, streams of data, disregarding ancient protocols on communication between those of different ranks, for the importance what was being discussed transcended such formalities. A resurrection of the Necrontyr? Overseen by a Parasite? On what merits can it claim such?
The argument in the hall grew louder and louder in every metric with which such could be quantified. It grew to a crescendo - then it was silenced. Not by the drawing of arms, as some of the assembled were close to doing so. Not by the command of a Triarch, as one had been considering. Not even by the demands of the upstart Parasite, as the right of it being the host of this meeting would have.
No, the voice that cut through the sheer volume of the debate was a meek one, a weak one even, but one whose very existence made it the single important entity in the galaxy in that moment.
Despite the power embodied in each of the necrons present, they all fell silent upon hearing the mere cry of a newborn child.
"Impossible." uttered Szarekh, the first to break the silence. His sensors combed through the being laid bare inside a cradle made of flesh, presented by the Parasite that called itself Tide. He paused for a second, running diagnostics to make sure that none of his sensors were malfunctioning, double checking, triple checking, to make sure that what he saw was real.
It was.
Slowly, carefully, and with more gentleness than Szarekh had ever commanded from the necrodermis servos in his hands, he reached into the cradle and lifted up the newborn child. A child free from the sickness that drove them in desperation into the biofurnaces, to edge of extinction. An existence that no one - not their greatest scientists, not the Old Ones, not even the Star Gods were able to grant them. An existence that the Galaxy had not experienced in over sixty million years.
A living, healthy, Necrontyr child.
As the Silent King lifted the bawling child up to be illuminated in the light of the chamber for all to see, he felt an ancient mental subroutine queue into his processors, a crude mimicry of a long-lost thought he knew he last experienced from when he was still a mortal being:
Hope.