Chances are, if they aren't doing a shared universe, barring Flash, we won't see a second version of the same character. So if Hal is in the JL Movie, I doubt he'll appear in Flash or Arrow.
A JL-lite on tv would probably consist of characters unique to the tv universe. Arrow, Atom, Black Canary, etc.
I only say that bc the show runners have regularly talked about needing DCs approval on using characters. Why refuse them the right to use certain characters if they're doing separate universes?
That's the part that will confuse me about the separation of universes. I mean, I'll go along with it if I understand their decisions. But not letting them use certain characters is weird.
Flash is the anomaly.
A JL movie with The Flash would make me sad. It would feel wrong. So we all assume who the members will be because of who the members have always been.
Maybe Flash is the key to a Multiverse plan...if they go that route. Because of the Speedforce and his history in the Crisis on Infinite Earths event, he's the character that can exist outside of the limits.
My ideal dream DCCU would be shared, I've made that clear.
But a notch below that would be, "fine, Arrow doesn't have to exist in the cinematic universe, but Gustin's The Flash could."
And since I don't expect that to happen, the notch below that is "Okay okay, separate universes but the Multiverse exists and it's acknowledged and used. The Flashes are essential for the audience to see that. Do something cool with that that Marvel hasn't been able to do."
If DC is known for big Crisis events, do that to show how they're different from Marvel.
Business is competition of course.