From Trekmovie:

David Ajala: A moment I wanted to share is something that happens in season 5. I remember speaking to Alex Kurtzman about this at the end of shooting season 4 and it was an idea that he shared with me and I think Michelle Paradise was the only other person that knew about this thing at the time. Then cut to season 5… we get to come back to Toronto and create something so very special. [Sonequa interjects “We did”] I’m so proud and happy that we got to do that because you know how amazing that was to do. And I can’t wait for you guys to experience the very secretive thing which I can’t talk about which we got to do.