I think Indy V is the only way we will see the rest of the RotLA figures made.
They will release two cases of figures: Case #1: RotLA Wave #2; Case #2: Indy V Wave 1
After that I would be willing to bet that they'll try a 3rd wave that brings in figures from all of the other previous movies, characters such as Donovan, Marcus Brody, Mac, Marion (from Crystal Skull), Dietrich (if he doesn't get squeezed into Case #1 above), Oxley, Willie (red sequin dress), Indy in tuxedo, Lao Che, etc... - it will be a wave of figures that they want to do, not a movie themed wave 'cause that would back them into a corner when it came to character choices.
I think they'll also release a few deluxe figures, perhaps they'll even try to give us things like a ToD Mine Cart or TLC Motorcycle w/Sidecar.
Let's hope we don't have to wait 10 years to find out!