So you decide once and for all how many copies you are releasing? Shaky technical terrain. Shakier legal terrain.
In the world of actual (not digital) goods, it happens all the time.
Like they might release a limited-edition of only 500 copies of something.
But creating such artificial scarcity for digital goods? I doubt they are even trying to do that...
They are selling "digital certificates of digital ownership"... But who needs that shit?