[SPOILERS for those not caught up on Arrow ahead.]
The season 6 premiere of Arrow, "Fallout", set up a whole dynamic for Oliver with the tragic death of Samantha on Lian Yu. With her dying breaths, Samantha asked Oliver to take care of their child, William. Oliver, who had previously decided to stay out of William's life until he was 18, was forced to suddenly begin raising his son. Juggling fatherhood, being mayor, and fighting crime as the Green Arrow, was a considerable challenge for Oliver during the first two episodes of the season - and in the cliffhanger for the second episode, "Tribute", Oliver decided to make Diggle the new Green Arrow so that he could focus on being a father and the mayor.
In an interview with EW, Stephen Amell talked about Oliver stepping down as the Green Arrow and how long it will affect the show. Describing William as the "game-changer" that inspired his decision, Amell says Oliver gave the mantle of the Green Arrow to Diggle with "a full heart," instead of "a heavy heart," expecting him to be able to handle it, though Oliver is obviously unaware of Diggle's recent problems in the field. Amell also commented on Oliver's future role in Team Arrow:
He’s out. He’s totally out. We have an instance where he has to hop back in, but it’s not in the capacity that people would expect him to. It’s in an episode called “Reversal.” He does have to hop back in, but other than the occasional visit, he’s out.
Amell says it was important for the mantle to be passed on to someone else because the Green Arrow is a symbol that the city needs. According to Amell, the Green Arrow can be more than one person, which is reminiscent of Iris' words to Barry in Tuesday night's episode, "We are the Flash."
As the season moves forward, Oliver will continue to deal with FBI Agent Samandra Watson, who remains unconvinced that Oliver isn't the Green Arrow. Oliver will try to keep to the sidelines, but it remains to be seen how long that will last, or if Diggle will be effective in his new role, considering his recent struggles with making killshots.
Arrow continues with "Next of Kin" on Thursday, October 26 on The CW.