Might be correct tho', when you think about chapter breaks etc, which do not increase spacing with line spacing changes but still affect total pages. If enough chapters end on upper half of page when space increases, then it will add pages proportunately in print.
If you do not page-break chapters in E-book, then the spacing between chapters will increase between chapter headings proportionately depending on line spacing. I know, weird, but computers do not think (usually), so what you feed it is what you get out.
Amazon counts print pages if you publish a print book first - otherwise, if you publish E-book first, then print book, it counts the e-book pages (always less) unless you contact Amazon and ask it to use print page count - after you publish it. Amazon will not change it unless both versons are already published.