I don't recall any reports in changes in video playback quality (but there may well have been). In general, I still find LR video playback quality subpar, and I generally play it back with the operating system's native media player. Select the video in LR, right-click it, do Show in Finder or Show in Windows Explorer, and then double-click the file there.
If you want more feedback from others on that issue, I suggest you create a new thread with a different subject line.