Haha, did that. Turns out she was correct.
Went back just after an SQ flight was called, and saw a bunch of people leaving.
Walked in asking " ah, so it's open now?"
Bit of to-and-fro until she realised I knew what the rules were and she told me the full story: apparently today the business class flooring is getting redone (they've had problems since it was put in) so they're directing J SQ pax and SQ elites to their first lounge (which appears to be the door on the right as you walk in) and other passengers to the NZ lounge.
I was still a tad sceptical until I arrived back in the NZ lounge, where the staff were a bit surprised I was back so soon; when I mentioned SQ turned me away they confirmed the floors are being redone.
Now feel like a bit of a prat
