Opinion:
Paul Robertson
The other thing that's important to mention is that mitochondrial DNA does not contribute to the sexual process at all, and doesn't contribute to the genetic code of future generations. M-DNA passes unaltered from generation to generation through the mother's line. Our M-DNA codes are ancient, with only minor changes made by mutations over the centuries.
It's entirely different from inserting nuclear DNA into a new person, where that code would replicate and combine with future generations of parents and blend itself into the new generations.
M-DNA donation is more like donating an organ than donating genetic information. It's just millions of tiny tiny organs instead of one large one.