The basis of this is a WhatsApp message that did the rounds a week or so ago, and was vaguely dismissed by BALPA as being bollocks (wasn’t the strongest denial I’ve ever seen however...)
Personally, and with no evidence whatsoever, I do think a deal has been agreed in principle, it probably has some elements from the above “deal”, and we are at the management (IAG?) sign off / legality check / how do we pitch it to members as a win stage.