GraphicGraph okay, this needs clarification.
This is in no way "pushing back against chat control".
This ruling only concerns measures defined in the German Code of Criminal Procedure (StPO). You can find a copy of it in English right here.
It specifically concerns section 100a StPO "Telecommunications Surveillance" (TKÜ). This section defines who police are allowed to surveil under which circumstances. Since it's the most invasive instrument in the prosecutions toolkit, the threshold that needs to be reached to legitimize its use, is enormous. (It also touches on the online-search (Online-Durchsuchung), but that is less of a concern here)
This ruling by the BVerfG set the bar even higher. Now, crimes that are punishable by 3 years or less of jail time, are not enough to warrant a Telecommunications Surveillance in accordance with section 100a StPO. So far, so good.
So, what's the problem now?
Basically, the StPO regulates active measures by law enforcement, that target specific individuals (suspects) and thus exposes their personal life to active surveillance and overall repressive measures. All the data that is collected, is overseen by humans.
ChatControl, as of now, would be an automated system that can't invade people's privacy, since it is a machine. In theory at least, no person should be able to see any messages or media, unless they contain problematic material. There also won't be any "random discoveries" (Zufallsfunde) that are not uncommon with classic surveillance by LEOs, why such high levels of criminality are required to warrant these kinds of surveillance attacks in the first place.
If you're not familiar with the law, it sounds pretty good; but once you know your way around it, there is no way this ruling will influence ChatControl in the slightest. It's just not the same situation.