If so, the Letters of Understanding are not evidence of a change in position.
I didn't charge that it was a recent change. If it's a deviation of the policy from the 1980's or early 1990's, it's still a change. The offical word in the literature used to be that it was akin to rape and transfusions should be resisted at all costs. This hasn't been changed in the publicly distributed WT literature as far as I'm aware. So it could be that this unoffical policy change took place a while back, but is being publicized more widely now.