Only if the next CoD is another Infinite Warfare level flop (by CoD's standards) and EA badly botches the next Battlefield and FIFA. But I guarantee there's no way FIFA is slowing down in sales this year, because this year is THE year.
The year? You mean a World Cup year? What if that actually decreases sales? If the World Cup game releases in June as usual then that may actually harm FIFA 19 sales if some people are happy to get their FIFA fix from that for awhile instead of buying a new game just a few months later.
Bet Shiken that COD would outsell Battlefield in 2018. http://gamrconnect.vgchartz.com/post.php?id=8749702