Were Birdboot and Moon from "The Real Inspector Hound" the inspiration for Statler and Waldorf?

[UglyMug]

I'm curious if Henson drew inspiration for these two characters from two similar characters in Tom Stoppard's play "The Real Inspector Hound"? "Hound" premiered in 1968 and Statler and Waldorf (according to the wiki) first appeared in 1975. I was searching online and all I could find was a brief comment on it in a Theater blog that mentions a connection, is anyone aware of a Henson biography or interview where he talks about this?