OK, just done some tests and results are:
iOS10 also don't accept BPLISTs with lyrics metadata during transfer (fails to send manifest) -- i.e. #12701 is still valid
- with Music app only some of the tracks has lyrics (e.g. Moby, 18, In My Hearth), but many tracks fails to show the lyrics (e.g. Sting, Brand New Day, Brand New Day)
- with Cesium music app _all_ songs are showing lyrics
Note that the Cesium app can show also some addition info like grouping and comment ( http://www.ventismedia.com/mantis/view.php?id=13564
Also star rating is still possible with Cesium (no longer possible with the Apple's Music app starting from iOS10)
So workaround seems to use Cesium music player .