That money has no strings attached, unless the amunt is about to be changed. An changes to the fee have to be agreed upon by both chambers, Bundestag and Bundesrat. The Bundesat, representing the individual states, means state parliaments have to agree first. That's the reason why the last fee increase fell through after one state feared backlash from the AfD leaning members of the CDU (Merkals party) and voted against it.

Once the fee is agreed upon, it cannot be changed either way with out every parliamnt agreeing to do so. The money cannot be held back by te "government" (we have coalitions, and those change regularly every 10 years or so). Neither can it be held back for state broadcasters (third programms) by the local governments or parliaments. Sounds pretty tempering free to me.

And the debate did happen in 2015, or didn't you see the same panel discussions I saw? It also happened in print and the public broacasters reported aboutthat debate in their news segments. The nature of these news segments being to report facts and not to debate.

It just turned out that only one party really opposed the opening of boarders, along with the right wings of the cnservative parties CDU and CSU. Thos are not the majority but rather a very very loud minority.