If however things don't work out and redundancy becomes a reality, and at the same time BA is still recruiting externally, then that is a very serious issue that BALPA, and all of us who are members, whether as BA, (ex) BMI mainline, or any other part of the pilot community, need to be prepared to take a stand against.
The very best they will be offered by BA is a place on the next available selection dates for DEP, competing to keep a job against all the external applicants. This is all they have offered to other BA subsidiary pilots faced with redundancy in the past at a time when external recruitment was ongoing for mainline.