Is this why Tyrannosaurus rex and Albertosaurus
libratus come out as sister taxa, with Daspletosaurus
more distant?
Maybe, but that part of the tree (carnosaurs and basal coelurosaurs like
tyrannosauroids) is quite undersampled anyway. Note that *Dilong* comes out
two nodes closer to birds than the three tyrannosaurids, and note that
neither the paper nor the supp. inf. ever mention this theoretically
surprising result -- presumably because it isn't surprising given the
sampling.
Of course, I don't think it matters much for deinonychosaur relationships.