The best thing about Supergirl moving to the CW and moving its production to Vancouver was that it meant that it was much easier to bring the DC/CW shows together for things like the musical episode. The worst part was that it meant losing Calista Flockheart’s Cat Grant as a regular. BUT SHE’S BACK, BABY!
Source: io9 – Forget Superman, Cat Grant Will Be in Supergirl’s Season Two Finale