Just one point on your article that tickled my funny bone...
You wrote, "The retailer says, "checkout will be available at 9:45 pm ET Monday night." I think you drew the wrong conclusions. B&H is owned by Orthodox Jews, and as such, their store is closed during the holiday of Shavuot and only reopens at nightfall when it ends. (This is indeed what the banner on their website currently states.) Although it is theoretically permissible to have the website fully functional, the owner does not rely on that leniency.
As an aside, this may explain the placeholder listings, as B&H employees will be forced to play catch-up with other retailers when they get into work on Tuesday morning.
(I myself am an Orthodox Jew, but I live in Israel where the holiday has already ended.)