They have inquired as to whether or not our commercial customers receive the same account opening disclosures as our consumer accounts - specifically about overdrafts.....

has anyone experienced this with the FDIC lately and if so, do you know why they are asking this?

I believe they are looking to see if you are providing the same protections and rights to commercial accounts that you are providing to consumer accounts.

I had an FDIC compliance exam last year. This did not come up. They may be asking out of curiosity, or the found some kind of problem at another bank and wanted to see how widespread it had become. The weird thing that came up at our exam was an obsession about when loan payments were posted and what we had disclosed or included in our notes. (We were OK.)

There is no regulatory requirement (that I know of) for you to provide these disclosures (or opt-in) to business accounts. Maybe they are concerned about fairness to small businesses. I don't think that would become a UDAP issue, but I could be wrong.