Thousands of pellet guns shoot straighter now that their younger brother is in the Army....

YGBSM. 

Mr. T (MrT4) said:

replaceable Cam Pin Recess/Cam Path

Where is this mentionied?
do you think it has anything to do with the metal piece (with "Virtus" written on it) which is bolted on the left side of the receiver on MCX/MPX?
Because it's where the locking recess is located on an AR

Does Haenel/Caracal Group still somehow related to the HK or are they both completely different company?

https://www.thefirearmblog.com/blog/2020/09/14/breaking-c-g-haenel-wins-tender-for-the-german-g36-successor/

Very surprised they beat out the HK416. 

While not perfect, the 416 is at this point a proven platform with a number of happy users, and per Emeric, has a superb barrel with a long service life. 

https://soldiersystems.net/2020/09/14/german-bundeswehr-selects-cg-haenels-mk556-carbine-to-replace-hk-g36/

The MK556 beat out the new Heckler & Koch HK433 which was developed specifically for this tender after the German government told H&K that their existing HK416 (adopted by the German Kommando Spezialkräfte or, Special Forces) was too expensive.

Interestingly enough, Haenel part of the Merkel Group, which is under Tawazun Holding (United Arab Emirates) (Caracal). So the Bundeswehr is essentially getting a lower cost HK416.

From the comments:

There were two engineers that after the HK416 went to Sig to produce the 516 with lessons learned from the 416. After that, they were hired by Caracal to make the penultimate piston carbine- the 816 as well as the facility that they’re manufactured in.

--> MK556 reportedly based on Caracal C816, overview begins 3:40

https://www.youtube.com/watch?v=GLghlFV_sL4

https://en.wikipedia.org/wiki/CAR_816

The Caracal CAR 816 shares lineage to the Heckler & Koch HK416. The principal firearms engineers for the CAR 816 were Robert Hirt and Chris Sirois. Hirt was instrumental in the development of the HK416. Following his time with H&K, Hirt was recruited by SIG Sauer to work with then SIG engineer Chris Sirois on an improved version of the HK416: the SIG Sauer SIG516. Hirt and Siriois were then recruited by Caracal to develop a rifle that was superior to both the HK416 and SIG516. From this, the CAR 816 was created.

Manufactured locally under Licence by C. G. Haenel

The designers hopped around.

That's a replaceable cam stop yes. I don't know if the Haenel has it but those guns were designed by the same people

I think Haenel MK556 is indeed has that replacable cam recess thingy, judging by this image. You can see a bolted metal piece on the left side of the upper,  though it appears to be smaller than the one on the MCX,.

Seems like that's what that is yep.

I think it should be made clear that the "Haenel" of today has absolutely nothing in common with the old "C.G. Haenel" company beyond buying the rights, from whom ever, to use the name.