It's kinda confusing. The email that they sent me says: Ø If you have changed your passport from ________, then submit a photocopy or PDF Scan of ALL pages of your current, valid passport (these copies do not need to be notarized/certified). Each individual must hold their own passport (including children); Diplomatic/Official passports are not acceptable. Otherwise confirm in writing (email) this is still your current passport for travel
But Appendix B says: Return the original to us with your passport/passport copies.
I'm assuming that given Appendix B is a generic form they send to everyone, we should really just have to confirm that the passport is the same one they've seen in the scans I sent them with the application. I imagine you have a very similar email, style?