What happened to the Havok engine Physics that were going to be added to the World of Tanks PC?

I'm still curious, whatever happened to the Havok engine physics that were going to be added to World of Tanks.  Why the long delay in adding it?

Also, why did Wargaming choose Havok engine physics when the BigWorld game engine that is used by Wargmaing for World of Tanks and other games naively supports another one of the other game physics software programs, PhysX?

World of Tanks 9.15 GPU Comparison and Analysis

Introduction:

World of Tanks updated to version 9.15 which added new technology to the game.  Now the game supports multi core CPUs and is not dependent on single threaded CPU performance.  This should allow for an increase in frames per second with the same hardware compared to earlier versions of World of Tanks.

For smooth game play you want to keep your minimum FPS(Frames per Second) above 30 FPS.  Games can start looking like a slide show below 30 FPS.  Games tend to look smoother and are easier to play when you keep your minimum frame rates higher.  Generally 50-60 FPS is where games start to look much smoother to most gamers.  Some people with 60 Hz monitors prefer to have their minimum FPS never drop below 60 FPS then enable V-sync to reduce the visual effect called screen tearing.  Other players have monitors that are capable of 75 Hz, 100 Hz, 120 Hz, 144 Hz, or faster  refresh rates and want higher average FPS in game.  Minimum and average frame per second are a matter of both game play quality and personal preference and can be limited by the hardware.  Maximum FPS isn't as important for game play as minimum FPS and average FPS.

There is a myth that the human eye can't distinguish any difference above 30 frames per second, so that having more than 30 FPS is useless.  In scientific testing, it has been proven that the human eye may be able to see differences in frame rate at over 200 frames per second.  One United States military test of pilots showed that they can be shown an image of an aircraft for 1/220th of a second and they can accurately and reliably tell what type of aircraft it is.  Other tests have shown that computer gamers can see a difference between 30 frames per second, 60 frames per second, and 100+ frames per second while playing computer games on newer monitors that have the capability of using refresh rates above 100 Hz.  The difference is noticed more by gamers who have previously played on 100 Hz and faster refresh rate monitors.  Also, some people say that television and movies are shown at approximately 30 FPS, so more than 30 FPS isn't necessary.  However movies and television shows often use motion blur to hide what would seem to be jerky movement due to being played at 30 FPS.

Another advantage of higher frame rates is less input lag and less game lag.  You may have a great ping and no packet loss, but if you are averaging 30 FPS it may feel that you have higher ping when you play because there is more lag in the game itself.  For example, if you play at 30 FPS, each frame is about 0.0333 seconds.  If you play at 60 FPS, each frame is 0.0167 seconds.  If you play at 100 FPS, each frame is 0.0100 seconds.  To many players, having higher frame rates feels and acts like having a better in game ping.  Some players feel that higher FPS in a game makes it easier to hit moving targets in game and to hit smaller targets in game.

Methods:

Replays:

I downloaded a replay from WoTReplays.com that had a combination of close range fighting around buildings and longer range and close range fighting around hills and trees. Its a T-54 replay on Murovanka.  The replay is available here: http://wotreplays.com/site/2713913

Computer systems used: