While fans were treated to a fantastic “Invasion” crossover between the four superhero TV shows on The CW – “Supergirl”, “Arrow”, “The Flash” and “DC’s Legends of Tomorrow”, the crossover wasn’t truly a four-way crossover, with the “Supergirl” episode only tangentially included in the event.
“Next year, we’re hoping to do a true four-way crossover,” executive producer Andrew Kreisberg told reporters during a press event earlier today. “The great thing about our dear friends at the CW and (president) Mark Pedowitz picking the shows up as early as they did has allowed us to start building the schedules for next season. One of the big things we learned from two years ago, which made the crossovers this year slightly easier, was building in shut-down days, where shows just went dark. The single hardest factor in doing the crossovers is actors’ availability because the shows keep going on. You’re basically juggling four shows worth of schedules.”
Kreisberg went on to explain why “Supergirl” wasn’t fully included in the “Invasion” crossover…
“The thing that we didn’t really plan on – because we weren’t aware that we were going to switch Supergirl from CBS to CW and it was really going to be part of it – that was the one show that didn’t have built-in shut-down days, so all the other ones did. Melissa [Benoist] ended up being heavily in Flash and then in Arrow, so Supergirl was the one we needed to shut down the most and it was the one that we didn’t have any opportunity to. Now that we’ve gotten the early pickup and we’ve started designing the seasons, we’re building in those dark days, and actually more dark days on Supergirl than the other shows, to make it a little easier.”
Source: Entertainment Weekly