That is certainly possible. But any removals were made as part of updates in the repository. I did upgrade repositories to PASS just before I discovered the problem in this thread. If part of the upgrade to VLC, which removed a lot of the associated apps, "could" have removed the "libnav4" and "libdvdread3" libraries.
But, I may well have had the problem before the upgrade to the PASS, as I had problems reading another DVD about two weeks ago and thought the DVD had gone bad. It could well be, those two libraries were not installed when I did the reinstall of 2012.8 KDE.
But that is merely a guess on my part.
Deb