You can use your current gamertag/account on the Xbox One. I'm a little weary to do this though. People that play COD games have a tendency to leave bad feedback on you as well as complaints that are not even warranted. I got 57% unsporting from that
game alone just for being better than the sore losers that left it. Microsoft said that recent 'offenders' may be placed in the "Needs Work" catagory on day one. I would worry with that it would take only a few sore losers on Ghosts to end up getting me
sent into "Avoid Me" with the trolls and that is just something I don't want to happen.
Thought I read somewhere that all the rep will be reset when you move over to the xbox one. Only exception is for the people who cheat or notoriously bad, their rep will stay. Found it. see below, found it on IGN's website
Given that Rep (Reputation) will now factor into Xbox One's online matchmaking (whereas it didn't before on the Xbox 360), will everyone's Rep be reset to provide an initial playing field? Since there are new rules, shouldn't everyone be able to demonstrate
themselves as good players right from the start? Or will players be penalized for past mistakes? In other words, will previous account infractions carry over to Xbox One?
WHITTEN: We will not carry over any of the 360 reputation scores into the new Xbox One reputation system. The majority of members will start fresh at the “Good” player level.
We will be working with the Xbox Live enforcement team that has identified a small subset of members that have recently had enforcement actions taken against them and set those members reputation to an initial “Needs Works” level. This will give those members
a chance to prove they can participate on Live fairly, and are not automatically placed in the “Avoid Me” classification where things like SmartMatch filtering will affect them.