That's part of what I meant. Let me try and say it more clearly:
For the Kanto places that had their original corresponding themes corrected in HG/SS, when you turn on the GB Player and go to a place that had "incorrect" music in G/S/C, the music that plays is not what it was in G/S/C, and they didn't use the R/B/Y 8-bit theme either, instead they made a brand new 8-bit theme for Cerulean, Fuschia, etc...
I'd like to add that the GB Player cannot convert certain themes to 8-bit themes.
The music in these Battle facilities cannot be converted: Battle Hall, Battle Factory, Battle Arcade, Battle Castle.