Looks like the version of Super Mario Cereal with the built-in amiibo has finished its run. The good news is, you can still get the cereal itself in this variant box, which should be available at multiple retailers right now!
Does this mean they plan to keep it on the market for quite some time? If so that's awesome, Nintendo doing things like these appeals to a lot of people and I know children definitely tend to go towards familiar faces on foods. I may just buy a box to keep as a collector's item.