I just finished retouching my Proluge for my comic The Changeling's Sister, and yes, I find there is absolutely merit to going back and make the start better.
Now a couple of things to consider: How long is your first chapter? In my case I have a prologus of only five pages, so its wasnt that huge of a load to take on.
Secondly: Do you have to fully redraw everything from scratch? I see a lot of redrawing, but I wonder if going back and make it all from scratch is worth it? Retouching my prologue I kept the line art I had already made, but adding more difference in line weight, texture etc, and redoing the colouring. Just those touches did loads for the old pages.
(I hope a comparison is alright?)
Old version from 5 years ago
New version with improved colouring, lineart and texture.