I get that people are exited over this teaser pic in Red Hood and the Outlaws #0 but come on let's be logical. Some of these suggestions I'm reading don't even make sense.
SPOILERS for the surprises in RHATO #0.
Let's ignore how long Bruce was or wasn't Batman and keep to the 5 years 4 Robins thing. Dick started at 15 and is now 20. We have no idea how long he wore the suit but the events in RHATO #0 happen either around the time he was leaving or after he stopped being Robin. We know this because Joker comments on how Batman needs a Robin implying Dick is at the very least thinking of giving up the sidekick job. No age is given to Jason but he's younger than Dick and older than Tim. Jasons' life starts to get worse thanks to the Joker when this panel is shown.