It is without doubt correct that the details that are needed to be passed are just callsign and an aknowledgment of the agency you are transferring to. I think the other info can be useful though, but not necessarily for the tower controller. It is very helpful for improving overall situation awareness of other aircraft, those ahead know exactly where you are (I have often made more of an effort of vacate the runway quickly knowing there is another aircraft very short final). TCAS displays or not, sometimes this extra info is extremely useful. I accept in the steady stream of uniformly spaced aircraft operating into somewhere like LHR this is not necessary, but those gentle nudges and hints to those around you are very handy in some of the aviation worlds less organised airfields!