I've noticed on some Kepub books at least that widow/orphan control is turned on, a feature I've never seen before on an ebook reader. But widow/orphan control works best aesthetically when there are lots of lines of text on a page (such as the 35 or 40 on a typical printed book page). On pages with fewer lines, it's more of an irritant (in my view) than a feature, because it keeps making for short pages -- and short pages visually signal the end of a chapter. So, it's like a fake-out: "Chapter's coming to an end! Hah! Fooled you -- there's more!"
I'm all in favour of having multiple layout features, but this one should definitely be user-selectable.
Widows and Orphans defined at Wikipedia