Whilst I agree - and fervently hope we won't have to live in such a world - I thought the same about the API copyrightability and that one is not exactly going

Whilst I agree - and fervently hope we won't have to live in such a world - I thought the same about the API copyrightability and that one is not exactly going the reasonable way at the moment. H&K has an US trademark consisting of just "MP5" in relation to a ton of things (though not video games!) so they could at least try make a case out of it not being purely nominative use and tie AB in court, if they wished. It would be PR suicide, but still, not the most stupid thing they have done.