You don't say how you performed the octave transpositions nor do you mention which track is involved. This means that the answer to your question could be yes or no (depending on your method).
I assume that you are talking about midi since midi is the only aspect of BIAB that can be controlled from the perspective of octave. I also assume you are talking about BIAB 2018.
1. If you varied the octave settings in "Options | Preferences | Channels" then, as far as I know, these settings are global and do not save with individual songs. I haven't tried it but I also suspect that they do not freeze when a track is frozen.
2. If the notation is on the Melody track and you used the very top menu bar's "Melody | Edit Melody Track | Transpose" (see graphic below), then this transposition is written to the Melody track and, as such, will be saved with the song.
3. For notation that is on the Soloist track, there is an octave transposition similar to the Melody's transposition above and, if you used this, then the transposition is again written to the relevant track.
There are a few other possibilities but I don't have time to consider them all at the moment (it's a pity that typing is so slow!).
Hopefully the above will help. If not, can you please provide more details that give as much information as possible.
LINKS TO MY BIAB/RB SONGS