I Dont Think So
The fact that a MAM thread is closed on this forum would have absolutely nothing to do with the supply of flight attendants by MAM to Qantas. I am sure Maurice has a contractual arrangement with QF and he wouldn't be silly enough to have an agreement which allowed QF to pull the pin on him at any moment unless of course that contract expires very soon.
There is of course nothing to stop the company from placing any newly recruited flight attendants under the umbrella of a different labour hire company.