Exceed (XYZ) Rank / Level

Ok so im wondering, as with the 'dawn of the xyz' starter deck coming out there has been a few cards (e.g Harmonic Waves) which make a card (not change) a level.

So the question is. Can an exceed (XYZ) monster be given a level with a card which gives a level, changes a level, or both?

You cannot change a Xyz monster's level because it has none.
And the OCG ruling says you cannot activate Harmonic Wave on a Xyz monster

the great thing about xyz are that they have rank, so cards with effects that affects levels cant touch them, pretty useful today