Here is a sign in a shop selling film CDs:In Britain or the USA, pieces would be omitted, because CD is a count noun. But use of pieces for countable things seems to be the norm in this part of the world.
Here is a sign in a supermarket:Again, we find pieces used to refer to something countable, apples.
I strongly suspect that this usage will become the norm in World Englishes. After all, it is perfectly clear, so everyone can understand it with no problem.
More on trends in the Google ngrams corpus
11 hours ago