Thanks to tsukikomew for the heads up.
“We are beyond thrilled that Colton will be returning to Arrow this season,” says EP Marc Guggenheim. “It was always our intention to have him return following his departure last season, but it was a matter of finding the right story line to pull it off. That opportunity presented itself in episode 412 and we can’t wait for the fans to see this reunion.”
Source:
Just landed in Vancouver to...BEGIN FILMING ON #ARROW AGAIN!!! 🙀😸🙀 So excited!!!
— Colton Haynes (@ColtonLHaynes) November 20, 2015