From what I can gather from people who've had their flights changed, as you say, it seems to be the Gatwick flights..I had email.....heart stopped as the words Tunis..
.Gatwick....and CANCELLED jumped off the screen.. So on re reading I was relieved to see my return to Gatwick (leaving from Heathrow) had been changed, by one day, to return via Heathrow. Luckily the apartment owner has said I can stay the extra day at no cost. Otherwise I would have stayed with partners parent. Luckily I had u booked leave I could use. I think it is only flights involving Gatwick that have been changed....i was rather happy loooool