Why a replacement for rakenet in Unity 5.1?

Yesterday i read somewhere in the forum that unity´s rakenet will be replaced with the new network solution from unity. Why has it to be a replacement? That way many of my bought assets will not work after 5.1 and also my own multiplayer game will have problems if i want to use unity after 5.

Do i have read it wrong?
Maybe rakenet can live beside the new network solution like the particle system, the animation system or the ui system!?

Would like to hear someone from unity on this, please.

 

Most packages which currently use Raknet will be updated to work with UNet upon its release so that issue will be resolved within a couple weeks of UNet's release

 

If this will hapen it is great but does not answer my question.
Can someone offical say something to it.

 

Raknet stays in until a later patch. They want to give time for everyone to switch over. Hasn't been specified which patch, but they don't seem interested in dropping everyone in cold water on this.