Or The Office without Michael Scott. Fair point but Erlich isn't as central a character as those other characters were, and I think they'll make it work regardless.
They easily moved passed Peter Gregory's death and it's not like they haven't just ignored plot holes before (e.g. Jared being shipped off to the middle of the ocean & reappearing as if nothing happened).
I really like the show, but I'd be fine with it ending after 1 or 2 more seasons anyway.