Technically, there was not a crossover with Richie Rich. Richie & Scooby shared a 1 hour block on ABC for a time, and the rerun cycle has a closing credit package that seems a wee bit out of place.
What's New Scooby-Doo debuted on WB in 2002, FWIW.
What's New Scooby-Doo debuted on WB in 2002, FWIW.