While his career transition to announcer on the Tonight Show was totally fucking odd, it probably came at the right time for him. He always seems to fall ass-backwards into success, and that move was no exception.
But had he remained with the show, what would his role be today? PC Howard would never make fun of a stutterer anymore, and Ass-Kiss Howard would simply abhor interviews mocking celebrities.
So what exactly would his role be on the show now? Segment producer, I'm guessing. I doubt he'd still be sitting there answering the phones.