Chase extended its British Airways partnership back in May and then in June American Express announced you’d no longer be able to transfer Membership Rewards points 1:1 into British Airways October 1. Presumably the British Airways-Chase deal precluded other card products from having 1:1 earning with BA.
It’s a far cry from a year ago when transfers were still 1:1 and American Express ran transfer bonuses on top.
But there’s a work-around.