probably be the last year of flashbacks.
It makes sense that Ollie would eventually run out of backstory - after all, at some point he's going to catch up to where the show began in season 1. However, don't expect Arrow to be an entirely present-focused show by season 6; the flashbacks may not be a part of every episode in season 6 and beyond, but there are still going to be flashbacks.
Speaking to IGN at the TCA Press Tour, executive producer Marc Guggenheim said that beyond season 6, flashbacks will most likely be non-serialized, and will delve into the lives of other characters on the show.
"We basically made a collective decision that Season 5 would be the final year of flashbacks. Next year, in Season 6, what we'll end up doing is we'll do some episodes without any sort of flashbacks. We've [also] established over the first four seasons of proof of concept that we can do flashback stories that don't involve what I call the island narrative, even when he's not on the island.
"We still want to make that part of our storytelling, because we do like them. We like when those non-island flashbacks sort of illuminate what's going on in the present day. That'll always be a part of the show and a part of the show's storytelling structure. It just won't be telling a serialized story... We would totally do other characters."
From what Guggenheim and his fellow producer Wendy Mericle told IGN, it seems like season 6 will really focus on taking the opportunity to look at other characters in flashbacks, once they're freed up from telling Oliver's story. "We might even do a flashforward. You never know!" Guggenheim said, suggesting Diggle as a character for whom flashforwards could be fun. In the immediate future, however, Oliver will remain the subject of the show's flashbacks:
"What's nice is Oliver is himself a recruit to the Bratva at the same time in the present day he's recruiting all these new people. There's a very organic, natural parallel between the two. There's a nice organic parallel with what Oliver is going through in the past as a trainee, and what Oliver's going through in the present as a trainer."
Guggenheim expressed his belief that the problem with flashbacks in season 4 was that he made a conscious decision to not make the flashback scenes parallel the present story. However, this had the effect of making the flashbacks feel out of place within the show, as though they were only there out of a sense of obligation. Hopefully the season will see this part of the show get back on track, just in time to finish Oliver's story.
Arrow season 5 is scheduled to premiere on Wednesday, October 5, 2016 at 8PM ET; The Flash season 3 is slated to air on Tuesday, October 4, 2016 at 8PM ET; DC’s Legends of Tomorrow will return on Thursday, October 13, 2016 at 8PM ET, Supergirl will make its season 2 debut on The CW on Monday, October 10, 2016 also at 8PM ET.
Source: IGN