Before the recent UI update, I was able to drag an album, or even a playlist onto the Queue button and it would be added to the queue in the same way as if I had right-clicked and added it.
After this update, it seems this feature has been either broken or changed in some way. I can still drag individual songs onto the queue button, but when dragging a playlist or album the Queue button is not a drop-target, it is greyed out. I can still right-click and add to queue, so this seems like possibly a bug?
I find it a lot easier to perform this action via a drag and drop, and it seems inconsistent to allow this for some items but not others!