I had a similar issue with double tier points for a BA Holiday where the DTP did not credit at all after the year reset. Got the same email. It seemed to subsequently correct itself about a week after and before i had a chance to moan more. I'm not sure if they they then went and did me out of lifetime tier points as i never bothered to check.

Not saying this is what will happen for everyone, but in my case it seemed to sort itself.