There are requirements for the CCTV notices already.. you probably haven't noticed, because they're tiny and out of the way. Plus a lot of establishments use non-committal language like "may be recorded by CCTV" (almost as if every retailer added the signs but only some of them added the tech).
It would be great if this was posted, boldly, clearly. As long as there are data protection limits (only 3 month's history can be maintained, data is unrecoverably disposed of) and accommodations for those who do not consent. (If every grocery store adopts the tech, how will you buy groceries if you do not accept these practices?)