I can scotch that rumour right now. There are no plans to award the WSO/WSOp Flying Badge to Cabin Crew. There is, however, a discussion ongoing whether they should join the Airborne Specialist cadre - if they did they would forfeit their Cabin Crew qualification badge. However, nothing is decided. Currently Airborne Specialists are drawn from Air Ops, TG7, TG1, Int and TG11 branches and trades. There is also consideration ongoing whether Flight Test Engineers should join them too - they complete the ~1 year long ETPS course and run airborne trials and operate airborne trials equipment.
Hopefully, this info puts this one to bed?