Again, hair-splitting. BA warned of the consequences of strike action. Depending on which side of the fence one sits, it could be seen as consequential action or punishment.
The fact that staff travel had routinely been withdrawn prior to any previous IA suggests that the company had established a precedent for such action which the union had accepted as fair and equitable (otherwise they would have complained about it before) The difference this time around is that BA are not proposing to return it with seniority. There is nothing to compel BA to return it with seniority. The very fact that the company has offered to return it in the first place indicates that the removal was not punishment. In his original talks on the matter Willie Walsh was pretty unequivocal that anyone who went on strike would lose staff travel totally. That meant not just whilst they were employed by BA but also on retirement. I'd suggest hat he has moved considerably from that position in negotiations.
Why should cabin crew have felt that they would get staff travel back with full seniority ? Just because your granny has always knitted a pair of socks for you for a Christmas present doesn't mean that you will always get a hand knitted pair of socks every year. At some point the good lady will shuffle off this mortal coil and unless you are able to persuade another member of the family to take up the role, the socks will become a thing of the past.