Hi,
This is probably H&K trying to protect the name of the their products in a growing market such as paintball milisim/ scenario ball. Personally I am surprised the companies (Spec Ops, Tippmann, BT, etc.) have been able to get away with the use of names and "designs" for so long. I honestly thought these companies had already secured the use of look and name rights from H&K.
Now mind you it is possible that H&K didn't mind at first but when they saw the replicating of the designs take off in paintball, someone said we better get in there and get something out of this. Reality is these companies took the time to secure trademark rights and such, none of these suits would exist. The other side is maybe H&K wants to get into the Mil sim market.