Germany's use of gas has basically nothing to do with nuclear energy. It's used for gas peakers (which are for now and were needed, whether some % of electricity is provided by nuclear plants or not), heating (which has/had nothing to do with nuclear plants) and heavy industry like steel (which wouldn't be able to replace their gas usage any easier with nuclear than with renewables).
The current government is full of hardcore ideological incompetents captured by fossil fuel interests that wouldn't recognize a free market if it threw € bills in their face. Merz in particular can "admit" whatever he wants, it was an uninformed talking point to get a few points on media as a response to a small time-limited news wave on nuclear - nothing else to it. He's easily triggered.
The previous government extended the runtime of the shutdown-ready plants because of the energy crisis. Shutting off the last few hasn't had any significant impact on industrial energy prices https://www.smard.de/page/en/topic-article/5892/216044/indus...