Apparently, what is driving the request is that one of the GE B767-300's has a seating configuration that is two too many seats for 7 Flight Attendants under the 1:36 rule and, as it is not economical to add another F/A, they are currently blocking two seats off. Also, at some more remote destinations where there are no reserve crew members, the 1:50 rule would allow dispatch of a B737 if one F/A becomes ill.
Management give strong assurances that they are not planning to further decrease the number of F/A's on QF services.