It's the "end of school year" holidays in America now (they go from August to June), and the back to school advertisements are starting to show up (like they do here just a couple weeks into the end of year school holidays), and one from Walmart includes several contemporary iconic hereos, including Optimus and Bumblebee, to promote licensed clothing for kids to wear when they return to school next month.
(regular American schools don't have uniforms, so they wear casual clothing)