Is there someone out there 2016 who do not want and need E2E encryption?

You can never trust the transport way, not even if the service is running on your own server.

And yes, there is something like OMEMO (double ratchet) which allows sending E2E encrypted messages to offline contacts. This is well documented and already implemented in XMPP clients:
https://conversations.im/xeps/multi-end.html
Of course this opens a new attack vector since the keys are cached on the server.

All this will be also made for matrix to reach the same privacy level which is already done in XMPP.

Don't get me wrong - its great people wants to implement new, open and secure conversation systems.
But at the end, the only difference between XMPP and matrix will be the protocol layer: HTTP/JSON vs. XML. And I prefer XML :P