Board Thread:Episode Discussions/@comment-25319479-20180719110008/@comment-25643824-20180720173349

@Ultimadude I disagree if it were a mutation of his genes then boruto and himawari would both also have 6 wiskers like naruto but they both only have 4 each. It is more probable that Kishina being a woman allowed naruto as a fetus to be saturated with Kurama’s chakra for a longer period (9mths) during gestation and boruto and himawari wouldn’t have been as saturated since naruto only provided the sperm.

Momoshiki never did no such thing what he stated is that naruto had no way to pass on his power to boruto then proceeded to turn kinshiki into a chakra and eat him, kinshiki thereby passing his power to Momoshiki. So this is most likely what Momoshiki was referring to, that naruto had no means of passing Kurama and his own power to boruto as the ootsutsuki are able to.