This is what you are trying to do (using your words as they apply on you not me or anyone else that thinks it is a bad idea to make coin shop players fight against players without coin shop).
NOTHING changes with icecrown if it does not get crossrealm, nothing bad happens to icecrown.
You are trying to force a whole realm (Lordaeron) to make all their items almost useless for pvp and you are trying to force 4500-5500 GS players to only be able to fight against 6000+ GS players.
But you have not understood anything of what I have written so I won't write anything else.