WMG / Get Smart

The funeral at the beginning of Get Smart Again! was for the Chief (at least symbolically).
Doesn't explain why 99 wasn't there, but maybe for security reasons only one of them could be?

Max was a much more competent agent/saner person when he began working for CONTROL.
His experiences as an agent got to him and caused permanent psychological damage. He and 99 are both repeatedly shown to have symptoms of PTSD (that are always Played for Laughs), what with Max jumping and screaming "Don't ever do that!" whenever someone sneaks up behind him and 99 reflexively punching Max whenever he tries to sneak up behind her to kiss her.

Siegfried is an age-progressed Hitler.
And Starker is possibly an age-progressed combination of Herrmann Goering and Joseph Goebbels.

CONTROL is actually older than they seem
In one throwaway gag, one of the undelivered CONTROL messages reads "The British are coming". So they've been around at least as long as the Revolutionary War.

99 had an affair before she and Max got married, then cheated on Max during their honeymoon.
In the 1995 revival series Get Smart Zack Smart is played by Andy Dick. In the 1989 Made for TV Movie Get Smart Again! supporting character Beamish is played by Steven Levitt. Look at those two - they could be twins!

The Vorlons represent CONTROL, the Shadows represent KAOS. They've both been active since the mid-20th century on Earth, manipulating the Cold War to their own ends. The whole charade is ended when the younger races realize just how ridiculous the conflict was and how one side really is no different from the other.