Tonight's season finale of Legends of Tomorrow featured Hawkman and Hawkgirl deciding that they wanted to go off and start a life together in peace now that Vandal Savage has finally been dealt with (three times). As a result, Ciara Renée - a series regular in season one - is now exiting that role. Falk Hentschel was only ever a recurring guest star, so his departure isn't quite so surprising.
"We went through the team, made a list of all the characters and started to think of stories for them," producer Marc Guggenheim explains about the decision to say goodbye to Hawkgirl. "When we got to Hawkman and Hawkgirl, we had trouble coming up with stories. The bow was tied so tightly and neatly with their story in the finale, that everything we thought of felt very forced. After 4000 years, they were no longer under the specter of Vandal, and we felt they need some time off. Bringing them back to the team as soon as the the beginning of Season 2 felt premature."
It sounds like they MIGHT make another appearance somewhere down the line then, though don't be surprised if other characters are also switched out moving forwad. "We have a very organic system in place to take a break form characters. The composition of the team is going to change; there will be some new faces on the Waverider. The season finale planted some very significant flags in terms of what the new concept of the show will be in season 2." Right now, the show is looking to cast a male and female regular to join the team, so we'll be getting some fresh blood in the series soon enough.
This is the second major cast shake-up to Legends of Tomorrow after Wentworth Miller departed Legends of Tomorrow but signed a unique new contract which will see him become a regular presence in The CW's comic book offerings. How that will work remains to be seen, but an Earth-2 doppelgänger would certainly be one direction to take things in. For now, we'll just have to wait and see...