Can anyone tell me which sets are in these bundles? I'd look inside, but I don't want to break the seals.  The sets were purchased from Costco and are dated 2001. I'm not sure if that's when they were actually bought, though

Bionicle.

Bundled Assortment A & B? Well I do know throughout the original Bionicle theme back in the day, LEGO liked to release combo packs that came in pairs each containing three characters for a total of six altogether. (I had one for the Rahkshi from Japan a long time ago but those guys are something else.) While I do not know how to find information specifically relating to what is in these boxed assortments, each bundle should contain a number of three Bohrok types (assuming I am interpreting "Bundled Assortment" properly). The individual set numbers are 8560, 8561, 8562, 8563, 8564, and 8565. The Bohrok had come out sometime in 2002 making the 2001 the copyright date I guess.

Unless someone knows differently, I believe you are fine to open those outer cases as what is inside should be the plastic canisters sealed ready for a store shelf to sell. For all I know each assortment could even be the special triple packs of 65109 and 65110 respectively which were the original canisters plus an extra helping of plastic wrap.

I just realized to ask, is there somewhere on the case stating something of content count as in how many items are in there? These look like the sort meant for the backroom over out on the floor though.