I’m sure they will at some point but it just doesn’t seem to be a priority. It’s not like they closed the manned tills, and the total number of items is quite low. Basically only applies to the packaged meat section and then maybe two handful of items a day, if you don’t shop in the morning you’ll probably never see a sticker.
My guess is that with other items they run an ordinary rebate well before the best before to get rid of stale stock but meat spoils too fast for that.