Shaving or cutting off hair does nothing to change the folicles under the skin so there would be no benefit as far as getting prettier hair. Chloe has had a couple of hair changes in the past few years and now is getting a nice dark blue silver coming in.
I think the reason this "wives tale" (people believe this for humans too) is that when you shave off all the baby hair it of course will grow in differently but really it was going to do that anyways
I say cut your little ones hair anyway
you like.
Oh and for anyone that struggles with mats I have found what I think is by far the BEST detangler on the market. I have used everything including cowboy magic and nada. So I bought tropi clean detangler spray not expecting much and the stuff is awesome!! No more painful brushing and her coat looks great too.