Clothes change much slower than software updates, and defending against a few adversarial examples is relatively easy, so this shouldn't be a problem.
I change my clothes at least once a day and add to my wardrobe on a ~weekly to ~monthly basis. Having been party to large system upgrades at even a reasonably competent company, I'd be shocked to find out that any surveillance system anywhere is matching that velocity.
So who says it has to be a few specific images? They could auto-generate a different selection to choose from for each purchaser and then print to order. Every individual article of clothing could be unique.
Some of these approaches are 7+ years old and still work.
As soon as they update the software, they run it over the stored video and investigate the differences. When they identify particular evasion techniques, they can flag up all instances and see what was done under their cover.