While the first set contained the usual extra parts of small bricks, in 40523 the first three bags contained spares, while in bags 4–7, there wasn't a single extra part!
This does not look like coincidence.
As explain e. g. in this answer, especially with small parts, there is always the chance of error, and Lego tries to deliver rather one part too many than one too few.
Has Lego improved their packaging systems so they are sure to always exactly hit the desired count? Is this something we can expect to see more often in the future?
Has someone had no more extra parts in other sets?