Not trying to be a humbug, but as a writer myself, I'm just injecting a little dose of reality. Writers are typically left off of those memorials, just like they're rarely mentioned in reviews. The actors and directors get all the attention. Did you know it wasn't until 1981 that a writer got a star on the Hollywood Walk of Fame?
It is still entirely possible that he'll be mentioned, but I'll be surprised (and pleased) if he is.