Yeah, as far as I know this has always been the official wording.

What makes me skeptical here is the use of "high precision" and what there could be to improve... a page was either viewed for the time necessary to read it or not. Over all readers of a book, it should not be too hard to find out the distribution of valid read times of a page.

Unless, of course, you don't have that data, but only some snapshots of which page is opened (e.g. when a sync to the cloud servers happens).

Shame the Kindle APIs are undocumented :/