Board Thread:Boruto Discussions/@comment-25319479-20170331095122/@comment-26010916-20170402183548

Honestly I don't think Boruto wanted to tell anyone about it - Neither Naruto or Sasuke, but I get the feeling that Sasuke approached him about it.He was eyeing Boruto since the dimensional battle, and afterwards when Boruto was standing on the Hokage Monument.

During his conversation in the flash back, he said that the Rinnegan allowed him to view what was going on.

There's clearly no logical explanation on why neither told Naruto. Either they felt it was useless information due to how irrelevant it has been since he acquired it. I mean if Boruto was in literal pain, felt odd, or was physically changing. Then it would make sense for the worry.

But since Boruto confirmed he has not felt anything strange since talking to Momoshiki, I can see why it's left alone.