Electronic books are published as distinct editions. Just as you don't get free credit for the paper back edition if you bought the hard cover edition, you don't get free credit for the ebook edition just because you bought a printed edition at some point. You've also never gotten free credit for updated editions of printed books either, just because you bought a previous edition.
I honestly see no logic in why one should get ebooks of previously purchased books for free - books have never been published that way and it makes no sense to me.
As far as scanning your books and converting them to say, PDF or epub for your own personal use, that would depend on the "fair use" aspect of each countries copyright laws. Many countries do seem to readily allow such individual copying for personal use, but given how varied copyright law is around the world, it's impossible to make a blanket statement about that sort of thing.
There are several companies that offer bulk scanning and OCR conversion to an ebook format for people willing to pay to have their private libraries converted to electronic books e.g. Blueleaf in Missouri for one I know of).