Soldier Systems Daily just posted photo of the new H&K 433 rifle. It is not based off of AR, but a mix of AR and G36 according to the original source.
There is no buffer tube, but it has easily interchangeable barrel. Selector switch can be set up as 45/90 or 90/180 degrees. The safety can be engaged at any time.
It is expected to debut at IWA soon
http://soldiersystems.net/2017/02/02/was-ist-das-denn-fur-eine-neue-sturmgewehr-von-heckler-und-koch/
narphenal from AR15.com posted these two photos
Edit: English brochure can be found here
http://soldiersystems.net/2017/02/14/hk-433-brochure-in-english/
From: Soldier Systems Daily