Or, on the other side of the Rudd-ian coin, he may have signed on to become a smarmy antagonist in the vein of William Atherton’s Walter Peck; which put his humor chops on the opposing side of the new Ghostbusters heroes.
With Peter Venkman and Dana Barrett both in play, there’s a possibility that Dana’s son from Ghostbusters II may have hung around Venkman enough throughout his formative years, becoming a smartass extraordinaire himself.