Maybe it was a predator Andrew Kreisberg thing? Supergirl is shutting down temporarily until April so Berlanti can catch up. He's going to be very actively involved from this point forward apparently. The speculation is Andrew Kreisberg and his dirty hands touched Supergirl more than any other. So Berlanti needs to step in and repair/create. Maybe with Berlanti back in full force intimately involved again we will see Kara as Supergirl in a different (but good) way when fighting her enemies. We will see.