Denying any responsibility for this is: The Thinker
The author writes:
To those who only started reading recently, this is a thinly veiled reference to the final appearance of Albert and his brother-in-law Steve, before they were wiped from existence in all timelines* by the gods of Ret-Coaneus during the Kaa-Nohn Crisis arc. It was a controversial decision at the time, but it I agree that it definitely needed doing. The only downside I can think of is that the cast page is now completely redundant**; if you see anyone on there appearing in any future strips it's because whoever wrote it doesn't know how to read memos properly.
* Them and about thirty-five other recurring characters I believe.
** Thereby begging the question, why has no-one updated it? The answer to that is because we're a bunch of right lazy beggars, that's why.