Could Die Linke conceivably lead a coalition in Berlin should they come in first in the next election?
Or to frame that question differently: Could a singing gay socialist jurist become mayor of Berlin? Now that should answer your question already. Of course he could, it's freaking Berlin.
No but seriously Die Linke in Berlin is among the most pragmatic and moderate among the different state groups of the party and was in the government several times. It's definitely possible that they could lead another R2G like in Thuringia. And furthermore what are the other options if things would stay that way? GroKo+FDP? If the SPD does that they would land behind both Linke and Grüne in the election after that.