That last entry was supposed to be the 20th Anniversary of David Letterman appearing on CBS.
If you recall in 1993, Johnny Carson retired from NBC's The Tonight Show. It was assumed that David Letterman was going to move from his Late Night program to that spot as Carson's heir apparent. The hosting duties went to another comedian: Jay Leno.
Letterman felt that he was screwed over and jumped to CBS where he became the host of the newly created Late Show at the same time as Leno's Tonight Show. A former Saturday Night Live and The Simpsons writer by the name of Conan O'Brien took over NBC's Late Night program. A similar episode repeated itself in 2009 when Conan O'Brien moved to The Tonight Show while Jay Leno was given a 9:00 PM (CT) weeknight talk show. That bombed horribly and was causing NBC's ratings to head further into the dumpster. Long story short, Leno returned to The Tonight Show and Conan O'Brien is hosting his own program on TBS. It is hard to believe, but the relationship between Letterman and Leno has thawed over the years. They appeared in a Super Bowl commercial together a few years ago.
So, why aren't you able to watch Letterman's first CBS program via the player I provided?
Apparently there is a copyright claim and the original holder has scrubbed YouTube of that episode EVER existing.
I'm sure if you go through some of my old posts you'll see some videos have been removed due to copyright claims or the YouTube accounts associated with those videos have been canceled.
The only thing I can say is....