Yes, 'behind the scenes' is the correct term, but neither 'pre-recording' or 'pre-recorded' is correct.
It sounds very un-natural. Some would call it an 'outtake' as something that wasn't included in the final version. But if it was a 'pre-recording' it gives the impression that it wasn't actually recorded. (That is in this context)
When they do movies and such, they often talk about 'pre-recording' photo shoots, giving the impression it was down before recording.
It depends entirely upon the context.
(Sorry if it seems to be a convoluted description)
Student or Learner