I know I should have written this right after The Flash season finale but unfortunately I have been distracted by video games and my other freelance summer job so yeah.
Now, I'm assuming that we all saw what happened to the season finale of The Flash season 1, where *spoilers for those who didn't* the flash runs into the wormhole so he could stop it from sucking all reality into nothingness, which could mean that in the Flash season 2, we might see some significant changes.
You see, the wormhole was created when Eddie shot himself, killing his descendant Eobard Thawne, which changes all the events that Eobard Thawne made. The particle accelerator would not have exploded in the year 2014, Barry's mother would have been killed by an unidentified murderer (watch Flashpoint Paradox), Harrison Wells would not have been killed, etc etc. basically the reality of the apparently alternate timeline that we have been watching in the Flash (And possibly Arrow's as well), would possibly change.
The Flash could create a version of the Flashpoint Paradox for CW
The Flash can basically reboot the CWverse if they need a reboot, just like what he did to DC comics' The Flashpoint Paradox. He can right the series' wrongs, create significant events accurate to the comic books, and maybe even connect other characters to the CWverse assuming that the studios owning these characters would allow it (Possibly Supergirl since I heard that the series is not CW).
How would the series be with these changes?
We can basically have our series more accurate to the comic books we read.
You can imagine Green Arrow now being how we want him to be. The sarcastic and funny comic book accurate Green Arrow instead of the dark and Batman-like one we've seen for 3 seasons now. We'd probably have Roy Harper back as Speedy, or if Thea Queen has speedy covered, Roy could be Arsenal or Red Arrow, We'd see more of Green Arrow's enemies instead of Batman's enemies, etc.
We'd have Flash sadly working alone on the series with no more help from Eobard Thawne, Caitlin Snow, or Cisco Ramon though like how he does in the Comic books. The Flash would have discovered what he can do with his powers alone, figure out how to beat his enemies alone, He'd have his metal made suit instead of the leather one we see (I'm basing all this from the new 52 flash graphic novels) etc.
We'd have Supergirl's universe connected to Green Arrow's and Flash's. You can imagine Supergirl suddenly dropping by from the sky to help Flash catch his enemies or something like that, We could have Supergirl added to the Legends of Tomorrow series, I think it would be great. It's all up to CW on how they're gonna do this all but all of this is possible IF they result to the Flashpoint Paradox from that wormhole.
(P.S. if Supergirl is brought to the CWverse, Superman would be hinted a lot more)