The answer depends on the extent to which you restock by using existing dungeon inhabitants (and treasure), and the extent to which the creatures and treasure is new.
As revealed in comments, the restocking introduces a monster roughly 1/3 of the time and treasure roughly 1/5 of the time.
If all of these monsters are new to the dungeon, then this means roughly one new inhabitant per three rooms per restocking.
Consider: How often do new monsters arrive to the dungeon? The usual means for new monsters to arrive are: from outside, from deeper caverns the dungeon is connected to, by spawning within the very dungeon, or summoned by some entities therein. If you restock once every in-game day, for example, and restock 6 rooms on average, you'll get 2 encounters worth of monsters per day. That's probably a lot, unless the dungeon is a part of a large and thriving ecology.
As a contrast, random encounters are restocking can be from existing inhabitants. For example: the carrion crawlers from room 7; the dungeon has a total of 30 orcs; the giant ants grow more numerous at a rate of 1 ant per day (1/6 chance soldier). Or you can look at the fiction and make intuitive decisions: since the orcs were rooted, the kobolds probably expand, so they will trap these two rooms and set a guard post over there.
I'm also running an old school game with Pathfinder rules. One difference from using OSR rules is that combats, and everything else, takes more time. If a single expedition is not over in one session, then restocking between can make returning very difficult, and will create anomalies like new orc tribes often migrating during player expeditions (since there is lots of random encounters happening while the characters are active, and fewer while they are not active).
Since Pathfinder expeditions can take plenty of time when there are several combats, and comparatively little time when there are none, I would recommend restocking once a day, or once a week, or by some other measure related to the fiction. Calibrate the frequency so that you get a plausible number of immigrants to the dungeon due to restocking.