Now I'm just a mere wannabe (hopefully a Trainee ATCO soon though, pending medical).
Anyway, this is out of CAP493 (section 1, chapter 3, page 12, at the bottom):
"ATC shall apply the minima as prescribed above, irrespective of any pilot
request for reduced wake turbulence separation. ATC does not have the
discretion to reduce wake turbulence separation minima."
I belive this means nothing will change after your meeting since the MATS is the founding document for ATC in the UK. But I do off course understand that you might want some real ATCOs to confirm that aswell
