I remeber that I it was mentioned on 'an' Anthology (book or DVD can't remember) that at the end of most live performances, the band would thank the audience etc. before the last song, so that afterwards they could immediateley leave the stage instead of having to give their thanks and walk off leaving the audience disappointed of their sudden departure.
Because the decission was made that there would be no more of the usual live performances, Pepper had to be a performance on itself, including the finishing speech before the last song. That became the Reprise: 'we hope you had enjoyed the show' etc.