Season 4 of "Arrow" came to an anti-climactic end with episode 23 titled "Schism" on Wednesday, May 25. However, when the CW show returns with Season 5 later this year, the events we covered over the past seasons may be inconsequential.
As "The Flash" fans know, Season 2 had ended with Barry (Grant Gustin) going back in time and changing something that altered the entire timeline. This is very similar to the plot of Flashpoint seen in the comic books. In it, Barry learns first-hand about timeline's ability to fix itself and somehow ensuring that what needs to happen happens.
Considering Star City and Central city are in the same universe, Barry's actions will have an effect on Oliver (Stephen Amell) and other characters on "Arrow." Although the changes may not be as drastic as Oliver not getting stranded in the Lian Yu island, but there will be subtle alterations in the story of each character that avid fans will be able to notice.
In the Season 4 finale of "Arrow," we saw all of Team Arrow bidding goodbye to their crime fighting life, at least for a while, leaving the clean-up of Star City to Oliver and Felicity. Although their decisions seemed final, the new development in "The Flash" might spell a difference choice of action for these characters.
The alteration in the timeline could also result in Oliver and Felicity (Emily Bett Rickards) deciding to remain a couple. The one alteration that would definitely make every "Arrow" fan happy would be the return of Arsenal aka Roy (Colton Haynes) and Laurel aka Black Canary (Katie Cassidy). The Flashpoint storyline in fact make stories so uncertain that even Laurel and Oliver could be the couple in the new timeline.
Hopefully, the CW will tease us with the changes in Star City during the months that lead up to Season 5 premiere of "Arrow." Based on that last for seasons, episode 1 of the upcoming season will most probably air on Wednesday, Oct. 5, 2016.