In the Netflix series Iron Fist we have this Stan Lee cameo in the final episode. Does this have any meaning, or is it just random like some other of Stan Lee's cameos? Did the other netflix marvel series have his cameos too?
In Netflix, Stan Lee having cameo as same character in all MCU shows:
His Daredevil cameo:
His Jessica Jones cameo:
His Luke Cage cameo:
And in Iron Fist, which you already spotted
He just portrayed as a honorable NYPD officer and their marketing face in MCU netflixverse. But remember like all his other Marvel cameos this one is also not to be taken too seriously and it's just a kind of puzzle for audience:
Because he is a watcher or works for them. Likely Uatu, the watcher that's assigned to watch Earth. Confirmed by Marvel in the Guardians of the Galaxy Vol 2. And keep in mind that the Netflix series are part of the MCU.
Marvel chief Kevin Feige has endorsed the popular fan theory that Stan Lee is playing the same character in all of his MCU roles. http://screenrant.com/stan-lee-mcu-cameo-theory-marvel-kevin-feige/
“Yes, we always thought it would be fun. Stan Lee clearly exists, you know, above and apart from the reality of all the films. So the notion that he could be sitting there on a cosmic pit stop during the jump gate sequence in Guardians was something very fun – James had that idea and we shot that cameo and loved it so much, you know, you see it a couple of times in the movie. It wasn’t in for a long time and we put it back in towards the end of the process where he references that time he was a Federal Express agent – we thought it would be fun to put that in there because that really says, so wait a minute, he’s this same character who’s popped up in all these films.”