[2023] Are there any plans for updating stockpiles?

In the current version of the game, under stockpiles in the room edit window, you can select which item categories or specific items you want permitted in the room.

That said, the update I'm finishing up introduces a ton of improvements to rooms in general, which includes added functionality to jobs/stockpiles. It makes it way easier to edit item permissions for rooms, but also lets you edit where items can go in more detail. i.e., you can select specific containers for things.