Colton Haynes will be a part of Arrow season 7, as a series regular, reprising his role as Roy Harper. Colton Haynes left Arrow as a series regular in season 3. Roy took the fall for Oliver and publicly declared himself to be the Green Arrow. Roy was imprisoned but eventually Oliver and the rest freed him. The character was forced to go on the run and his fugitive status is the reason that Oliver's sidekick was no longer apart of the team. (The real reason being that Colton Haynes wanted to move on from Arrow.) Now though the actor is back full-time.
This news comes as a bit of a shock as Arrow recently wrote off Roy (again). Colton Haynes returned to Arrow in the season 6 episodes, "Doppelganger" and "The Thanatos Guild" to usher in the exit of Willa Holland as Thea Queen. Roy and Thea rode off into the sunset, after a long time apart. Evidently, their happily ever seems like it will be ending prematurely.
CBR broke the news of Haynes' return. In a statement, Arrow's executive producers said of the new/old series regular:
We’re very fortunate and excited to welcome back Colton to Arrow. While we’ve always enjoyed Colton’s returns to the show, we couldn’t be more thrilled to have him return as a proper series regular and we’re very excited about all the creative opportunities Roy Harper’s return affords us.
Arrow never really said a full goodbye to Haynes or Roy Harper. After his departure in season 3, Haynes returned briefly in season 4. The character also appeared as a memory during Arrow's landmark 100th episode, "Invasion!" Although that was mostly created with archival footage. Still this is a huge reversal on the status quo of Arrow. Roy's return suggests a lot about the future of the series.
As mentioned, Roy's return does change the perception of Thea's goodbye. Thea left Star City with Roy and Nyssa to destroy three Lazarus Pits in "The Thanatos Guild". Though the mission was Thea and Nyssa's "responsibility," Roy pledged to go with to be by Thea's side. Now things will have obviously changed. While it's not guaranteed Roy will be in Star City for Arrow season 7, the possibilities are very, very high. This will, obviously, make it a little difficult to help Thea on her international Lazarus destroying mission.
Arrow doesn't necessarily need to break Thea and Roy up (again) to have him return to Star City. It will, however, take a lot of explanation to justify why Roy is around and Thea isn't by his side. Thea could send Roy away to keep an eye on Oliver or Roy could just figure he's better used in Star City than trying to destroy magical resurrection pits. While Thea's departure seemed final from a show perspective, the mission wasn't meant to last the rest of her life. However dire it might seem, this could just be a temporary separation between the two.
At the very least, Roy's return will shake up the dynamics of Team Arrow. Arrow season 6 is currently delving into a story that has seen the team split in two, with the new members forming their own crime-fighting unit. John Diggle, Oliver's right-hand-man since season 1, recently quit the team too over a dispute with the Green Arrow and his team leadership. Roy's return suggests that Oliver will at least have one his original allies by his side when the show returns for season 7.
Although given the series' penchant for twists and how much the endgame of the current season has been kept shrouded in mystery, nothing might be that simple.
Arrow continues Thursday, April 12 with "Fundamentals" at 9pm ET on The CW.