What happened to Phil Hartman's Simpsons characters after his death?

I’ve only seen The Simpsons on DVD, so I’ve only seen the first five years. What happened to Hartman’s characters after his death? Did they disappear from the show?

They just don’t show up anymore.

Simpsons retired Phil’s characters (Lionel Hutz/Troy McClure).
They also retired LunchLady Doris the Lunch Lady/School Nurse when Doris Grau passed away.

Gil (the character based on Jack Lemmon’s pathetic salesman from Glengarry Glen Ross) now fills the role of “incompetent lawyer” that Lionel Hutz once played.

I like the Gil character. But when he played the lawyer, it felt so hollow. :frowning:

They sleep with the fishes.

They retired Lionel Hutz, Troy McClure & Lunch Lady Doris; however, they do show up in the background from time to time. They just don’t speak anymore.