I have a quick question - can anyone confirm for me, that you old manuscript gets deleted when you update your E-Book? It's good that you can update the book at any time, but please can you tell me if Amazon bins your old book?
When you upload a new version of your book it loads over the top of the old one. I don't think they actually remove the old one, it just drops into a virtual bin somewhere. To my knowledge, once the new version is uploaded, the previous version is irrecoverable. (No doubt someone will let me know if I've got that wrong.)
New buyers will get the new (updated) version. They won't even know an earlier version existed.
However, the old version still exists somewhere, because if someone who bought it earlier downloads again (say, to put it on a second device) they'll get the same version they got originally. Same if they delete and re-download.