In ArcMap you can snap annotation features to other geometry. In Pro, you now have to "eyeball" the placement if you add new annotation via editing or decide to move the placed annotation for some reason. Annotation layers tend to persist once they are created and tend to get used in more than one project. Sometimes you just need to add a few annotation features to an existing annotation feature class. Snapping is greatly desired for manually placing annotation. For some reason, ESRI engineers just decided to do away with snappable annotation in Pro for some reason.
