I'm pretty sure it will have no effect. It will effect the clans and groups possibly, I'm not sure, but I'm almost positive they send a code to the email you use for CoD Elite for the maps. So I wouldn't worry too much, but I'm not sure if that's right myself, I want to ask or someone to confirm that I'm right. Looks like we'll both have to wait for an answer.

All you have to do is unlink your account to elite than link it again ,that's how I did it

Yeah, Im havinf the same problem too. I changed my gamertag three times and its still my original gamertag I had before. Im also thinking about changing my gamertag again, I hope if I change it will change on elite.