I think that Newsletter probably added more confusion to the issue. It should be addressed again with more clarity. Oil fumes from the bleed systems / AC packs will smell like “dirty socks” too.

If it’s coffee on the AC pack you’d probably smell dirty socks once the packs kick on at the gate when you turn the APU. If it’s coming out after APU Shutdown and engine bleeds open up it might something else.

I had the smell too on t/o roll and it dissapated. I remembered that sock smell file and figured it was just a stinky pack. The FAs didn’t notice and the we felt fine. We still called it in to be sure.