Has been awhile since I’ve been on BA, but in my experience it was always printed in emails/MMB 2x23 (well, ever since they reduced it from 3x32) with an official understanding somewhere that the excess to 32kg for each bag was waived for First, Club, Gold, Silver… but they never ever communicated that very well.

The waiver up to 32kg was usually printed somewhere if you hunted around for it on the web site.

So as mentioned above, it should be 2x32, but finding that in writing can be difficult. I’ve never had an actual problem at check-in with this however.