I don't think anyone truly knows- with the exception of TPL. Many thought the German recert was a big deal - this hasn't been proven yet. A good patent attorney could probably make a good assumption as to what is really going on here.
My "uneducated" guess is that they want the 336 recert so they can attack with all guns loaded - the German recerts and all the USPTO recerts. Companies may be more reluctant to challenge us in court with that kind of back up - and TPL and Patriot are waiting to gather it all before they come out swinging. It may be premature to threaten a company to pay up for infringing on the 336 when it "technically" hasn't been recertified "yet". I certainly won't be offended if anyone tells my I'm way off base - LOL.