okay i found the solution - if anyone ever runs into the same issue as me do the following:
go to your wow directory → retail → WTF → open config.wtf
delete the following line:
SET VoiceInputDevice “{0.0.1.00000000}.{69005ee6-c452-4ef6-b1ac-ab359a47a47f}”
it seems that when the config already sets a device the whole tab wont show up, if it is “unset” you’ll have that tab back