Who else asks for it? Heathrow is the only place I've been to that expects the info on first call
You obviously don't fly into Gatwick then...or Stansted, Luton and London City for that matter.
In addition to wake vortex, we check the a/c type so that there is no confusion when you are handed off to tower. If there is any type of emergency, they will be able to tell the fire service the a/c type. They may be issuing a conditional line up clearance against your a/c...rather beneficial to know then what a/c you are flying wouldnt you say? Stand allocation? I could go on....