There will be no issues as I see one of two things happening.
1. You need a special equippable item to summon your wings. And I'm sure the item will be account bound.
2. No item, but Wings are tagged for CE characters only. Sell a CE character to a person who only has reg version and he/she can't summon the wings.
Adding to that, I really hope these Wings are a simple toggle, and don't require the equipping of an item to summon them. Who wants to waste an armor/weapon slot on something purely aesthetic? I want to have them on at all times, and still have all my slots available for useful items.
Maybe just have them in the form of a potion in our bag that we cast once and lasts until we dismiss?
Please Blizzard, no armor/weapon slot needed to summon wings!