I have seen these questions regarding label rotation and map rotation via the print composer. One of them explains that the labels are rotated with the map, which I am looking for but am unable to get working for QGIS 2.8.3.
The second image shows what happens when I set my map rotation (270) to fit the map contents correctly into the desired paper size. The labels stay where they were, while the map rotates. Adding 270 as the rotation parameter on the labeled layer has not helped.
Not sure if this could have anything to do with it, but the labels are a concatenation of two fields (e.g. concat("field1", "field2")). Edit : This doesn't seem to make a difference for my data.