Maintenance minder was A6, now B6

2025 pilot TS with 9,700 miles. Maintenance minder came up for oil change with code A6. Dealer did the free oil change, but vehicle came back with 100% oil life and maintenance code B6.

So - is the diff fluid really needing changed or is this a message for upcoming service? It seems odd that it went in with a 6 and came back with a 6 if the fluid isn’t need changed.

I’ll call dealership and ask in the morning, but thought I’d ask the hive.