The Idea MUFC_FAN is not bad, but why would MON be getting 3 more A321 aircraft this summer, which leaves over half the fleet flying schedule, 19 in all.
Also it is believed that Easy my be trying to off load some of the larger airbus's from the GB merger as they do not fit in with overall big picture.
Yes the A300s, A330s and the B767 are planned to be disposed in the next decade after the B787s arrive, but so are a few B757s as well this year.
I think you will find this is just one big rumour and if any truth was in it, a statement would have to be made to stock market.