Impossible to really tell before we see at least a three months trend starting from November 2014. During last gen it happened different things in different years: sometimes Halo (or any other big system seller on any platform) launch and/or BF sales were revealed as just Xmas sales in advance, other times the momentum created then was kept or even increased.
Not to mention that this is a function of not jut one variable, XBOne sales trend alone, but two, PS4 sales trend too.