They most likely haven't said anything because they're still in talks about what to do. They've been pretty clear that bringing back elephants would mean a rennovated or new complex, so there's the cost factor to consider. Then of course they have to consider what housing elephants would do to their affiliations with strongly anti-cap organizations like PETA, PAWS, etc.
However I must agree with other users here in saying that it is unlikely that the zoo will opt to bring them back. Despite what was released by the zoo, it doesn't feel like a coincidence that their relatively young, fertile bull went to a sanctuary versus a bachelor holding or breeding facility. They evidently value their partnerships with anti-cap organizations, and I would be shocked to see them jeopardize that in favor of having a big ticket animal.