Not sure if this is really a bug or an improvement.
In the Object Properties panel, the drop down presented to allow users to change the object layer doesn’t reflect the parent/child nature of layers/sublayers. This can be a bit confusing if you happen to have layers in “groups” which have the same/similar names.
In the image below, the top part is the layers panel. The lower part is an open drop down of the layers, in the object properties panel.