In Shakespeare's "King Lear," why does the Fool disappear after Act III with no explanation?

There is strong stipulation that the Fool and Cordelia are one and the same, not unusual for heroines to disguise themselves as men for that time.

King Lear seems to identify the fool and Cordelia in the last scene. ("My poor fool is hanged!")

Mind you, other explanations consider his comment: "And I'll go to bed at noon", a line that might mean that he is to die.

http://www.pathguy.com/kinglear.htm

I have long preferred the idea that the Fool disappears because Lear has become his own fool -- and thus acquired his own wisdom:

[etext.virginia.edu/cgi-local/DHI/dhi.cgi?id=dv4-70] Link no longer exists