Microchip is continually creating new parts, and it takes time to examine each one, find the changes they've made and adjust the compiler accordingly.

Just making new .inc .bas .bal files is not always good enough to be able to use a new chip.
They move registers and bits around at will and PBP has to account for the changes.
They don't publish a list of "Things that are Different", so every chip must be evaluated and tested separately.

There's a large number of chips that will be added in the 2.60B patch. (almost ready for release)
The 16F1824 is one of them.

All of those chips are also being added in the latest melabs Programmer software v. 4.40. (this week)