That's what I think as well. Most likely just daily pricing updates for the exact legal reason SoyViking says.
I worked IT in grocery for a long time. The company I worked for was starting to sell these as I was leaving so I don't know a lot of the behind the scenes talk anymore, but the general thought was just for it to be a replacement of the paper labels that they usually replace weekly anyway. Maintaining shelf labels is actually a huge pain in the ass.
Not the whole time. Sometimes you get put in stupid looking underwear so you can shit yourself without dignity while everyone laughs at how smelly you are.