I've been playing since a few weeks before B5 came out so can somebody tell me why there are still sounds that I've never heard (I've played a lot in that short span. Prolly 7 hours on average a day.) Like the hud\marine_armoryupgrading.wav
or hud\marine_commanderidle1.wav These from an older version and never taken out or like the "we need better players" and nobody uses them?

Armoury upgrading is indeed an older version
"Commander idle" still plays, but you must be a really awful commander to hear it, or for some reason have just wandered AFK for a bit. (Which, thinking about it, means you would not hear the sound anyway...)
The easter egg sounds still play, and can be forced to play by admins using AMX mod. Aditionally, the easter egg probability can be set by a server cvar, whose name escapes me.