This article from three years ago suggested the A380 retrofit would start in 2023 and not finish until 2025: https://www.executivetraveller.com/n...80-club-suites
But this was written before the pandemic and we now know the 777 retrofit programme is running late plus I believe the 788 and 789 fleet were next. So the poor A380s will have to continue for some time which is a shame as they should be the flagship of BA and customers love them but they will soon get a bad reputation if matters deteriorate further.