These same discs are sold with a "Guarantee" as archival discs that are tested with heat/stress to last that 100 years, but any MABL disc really should,and they're much cheaper if you just get regular MABL discs.

Is there any kind of 'binning' going on that would make them different? A lot of things are made on the same assembly line, but after QC testing certain batches may be treated differently depending on the results.