The Firearm Blog has new photos of HK433 from AUSA 2017. The article gives some insight in to why some designs were made as well as the following article stating that H&K submitted both HK433 and HK416 for new Bundeswehr trial.
http://www.thefirearmblog.com/blog/2017/10/11/hk433-close-personal-ausa-2017/
http://www.thefirearmblog.com/blog/2017/10/11/hk416-hk433-submitted-bundeswehr-rifle-trials-hk-confirms-ausa-2017/
Soldier Systems Daily also has some photos as well
http://soldiersystems.net/2017/10/12/ausa-17-first-display-hk-433-us/
From: The Firearm Blog