Why is comic book guy never shown in any future themed episodes?

Answer 1

Since we are not the writers or producers, we can not answer this.

Answer 2

Like Solar said, we can't answer for sure, but I'll venture a guess: CBG is always shown as obese, not eating at all sensibly (constant junk food), and has even had a heart attack ("Worst Episode Ever"). Maybe there's a collective assumption that he's going to be dead!

Comments

That would be too bad since he's the only one I haven't seen in old age form.