I suppose it depends on the name. He is likely to get asked if his name is shortened, but does it really matter?

My sister's name is a shortened version of an old-fashioned name and she gets asked about it a lot, but it may also be because it is usually known as a boys name (just with different spelling)! I used to work with a Steve and that was his given name. Everyone assumed his full name was Steven which I guess would have gotten annoying at times. But I personally don't think it's that big of a deal.

Heck, if you've found a boys name you are happy with then go with it! Boys names are SO hard LOL!