While those bullets due look quite awesome and I don't deny that they would cause extreme damage and penetration to both surfaces and flesh, there are two problems.
1. Extensive rules governing warfare have been made over the course of time to prevent casualties, accidents, less than humane incidents, etc. Hollow point bullets have been generally unused in traditional warfare due to the grievous injuries they induce. I can't imagine these bullets being used in standard warfare.
2. These would not and should not influence CoD. CoD already breaks a lot of the aforementioned war rules, especially, if not exclusively, in their campaigns. This would be over the top. Add in the fact that CoD doesn't have to adopt new advances in technology to their games and that people already complain they die too fast and the methods in which they die are unfair, unreasonable, and/or unrealistic, adding these into CoD in any way, shape, or form would probably be to the ire of the players.
But again, those do look pretty sick.