I'm not a fan of the post-TOS PD, but that's just silliness. Who is Janeway to decide what the Ocampa's natural evolution should be? And what about the Kazon? She just became their enemies and denied them access to a balance of power changing technology. TNG-era PD would say that's a no-no. Janeway seems to be adopting a sort of Kirk-like flexible TOS-era PD interpretation, which would be ok, EXCEPT that for other situations in Voyager she's a strict regulations enthusiast. It just shows that Janeway was written so inconsistently and that they didn't get a good handle on her character.
Does "natural evolution" include the exploitation of their world by a being from outside the galaxy? All she is doing to this area of space is removing an alien presence that has distorted both the Kazon and the Ocampa's existence.
And I think it is only natural for Janeway to take a more Kirk-like, case-by-case approach to the PD as she travels through the DQ. Sometimes inconsistency is what makes sense. As a parent, I've learned that I have to deal with each child as an individual--what works to help one child fails with another. Strange as it may sound, inconsistency can be more fair than a rigid approach.
I don't really think there IS such a thing as "natural evolution." Was an asteroid impacting Earth's evolution not a part of its "natural" evolution because it was an event caused by an "outside" object? We just have to do the best we can with the info we have, which is why the PD is stupid and makes no sense.
However, in the "caretaker" scenario, Janeway's responsibility was getting her crew back to the AQ, not getting involved in local politics.