I know this is very unlikely to happen due to a number of reasons like the movie or DC's Silver Age nostalgia, but I was thinking about the League and how some members are allowed to grow and move on, while The Flash seems stuck in the past even thought for a long time he was the symbol of character progression through Wally.

Superman and Batman can grow a little older, have kids and marry.
Simon and Jessica are now the League's GLs, not Hal. Hal gets to do his own thing in space.
Cyborg is a JL mainstay
Diana keeps getting rebooted, but she's really the only major JL symbol like the Flash who doesn't really seems has progressed much.

Barry is back to Silver Age, and he isn't even married. He's taken several steps back and so has Wally.
The Flash was for a long time an example of DC's evolution. Wally was the one sidekick who got to replace his former mentor and make the role his own.

Now Barry is back and Wally is basically irrelevant aside from the mediocre Titants book.

How would you feel if Barry and Wally got the GL treatment?

- Wally would get to have a solo, return to the League and deal with the usual Flash set-up.
- Barry would also have a solo, but like Hal, would be centered around expanding his own corner of the DCU. In Barry's case, I think his main mission should be protecting the multiverse from Crisis-level threats. He died for this once and it would be a great role for him to fill now. He'd still be based on the main Earth, and would be married to Iris.

This would effetively restore most pre-FP continuity, giving strong roles to both Flashes without feeling like DC is taking several steps back with these characters.

The books would be:

The Flash: Wally West
Barry Allen: Flash Prime

Plus their apperances in JL and maybe a new Multiversity book where Barry could have his own team of multiverse protectors.