Myles is somewhat OK, though the y makes it less good than
Miles. I'd be happy to see a young
Miles, actually.
Mikaela is just plain awful.
Michaela at least looks authentic! But in those parents' case, I'd have gone for
Michele (or
Michelle, but I've got two excellent
Michele friends, so ...).
As for the matching initials, I find them miserably silly. Unless for some reason everyone in the family has to have an M name, and even then it just spreads the silliness more thinly.