Gosh, do you mean me? And there are other forums apart from BA?
What I heard - via HAL - was that Cathay had come up with a clear design and plan for the new lounge but shortly after starting a series of structural issues (major wasn't the word I heard) meant that to complete the design other unexpected activities would have to take place first. Furthermore the workforce needed for the work, and who need clearance, weren't scheduled to be available for the revised timescale. Now that is lacking in specifics, but in the speculation arena, the T3 building in this area is quite old and it wouldn't surprise me if some unexpected electrical, plumbing and/or structural support issue(s) was/were uncovered. Or perhaps asbestos. But that's in the speculation territory. I went past the area the other day and there was definitely work ongoing, though traditionally most construction work inside LHR takes place between 21 hrs and 04:00 hrs.