No es que se apode Buzz, es que a día de hoy es su nombre actual, no Edwin Eugene. Como fuente podría valer la sección FAQ de su propia página, http://buzzaldrin.com/faq
---> What is Buzz Aldrin’s real name?
Buzz Aldrin's real name is, in fact, Buzz Aldrin. He had it legally changed to Buzz in the early 80's from his given name Edwin E. Aldrin Jr. The name “Buzz” evolved from his sister Fay Ann's mispronunciation of the word “brother” which became “Buzzer.” By fate, or by coincidence, his mothers' name was Marion Moon