It is not really acceptable to say 'changes will be happening from May 30th' but not announce what the changes are. So they MUST either:
1) announce the changes shortly, and well before May 30th; or
2) announce the changes on May 30th but have them not be effective for a number of weeks or months.
I'm personally surprised that they're changing partner redemptions; I thought BA would be going the way of fare-based redemptions on their own/IAG metal, but keeping partner redemptions the same.