The above measure being confirmed by the German interior ministry

Amid worries about new virus strains growing to be the dominant mutation spreading across the country, Germany has been reported to consider tighter travel curbs. So, this is in part to do with that and they may even enforce stricter air travel moving forward as well.

If you're wondering about the latest update to the virus situation in Germany today, no you haven't missed anything. RKI hasn't updated their dashboard yet.