In the esri js version 4.7, the feature layerview's watch method doesn't seem to be working as expected. This worked fine in the 4.6 version.
Consider the following example:
In this example, I am simply adding a feature layer and trying to watch the updating property. If you check the console logs and zoom in / change the extent, the console log never gets called. There is different behavior if you change the version of the js api referenced to 4.6.
It seems to be a fairly significant bug to me.