Kreisberg says: “We’d love to have him back, but right now, we’re still trying to figure out what we’re going to do for the rest of the season. We loved working with him, he’s amazing in the part and we’d be lucky to get him back.”
We can also guess this means Tyler Hoechlin's Superman won't be appearing in the upcoming CW DC crossover, which is a major bummer as Superman was a big part of the DC Comics Invasion! storyline.
Regarding why Tyler Hoechlin's Superman isn't scheduled for more appearances, a previous report mentioned WB/DC only approved the use of Superman for the two episodes, and ratings on Supergirl seem to be suffering as a result.
Tyler Hoechlin's Superman appearances on Supergirl saw 3 million viewers for the season premiere episode followed by 2.66 million viewers. The following episode with no Tyler Hoechlin Superman saw those viewers return drawing in 2.65 million, but the next episode, again minus Superman, only brought in 2.22 million (albeit on Halloween). Last week's Supergirl went up a bit, but still below the Superman episodes with 2.47 million viewers. Now did Supergirl lose viewers as a result of losing Superman? That's a good question. Viewers may have tuned in for the third episode, expecting to find Superman, but bailed on the next episodes realizing they are absent of the Man of Steel.
Seems obvious: Bring back the Tyler Hoechlin Superman or give him his own series.