My understanding is that Introduced gets applied to descendant places with Unknown status without using that special tool – just automatically when the parent place gets changed to Introduced by anyone. And when the special curator tool is used, it will then change everything, not just the unknowns.
If continued, that automatic behavior needs to come with an error check, and the unknowns should not be changed to Introduced if any of the descendant places have native or endemic status for that taxon.
As for completely eliminating the special curator tool (apply establishment status to all descendant places), while I agree with your reasons, I still have mixed feelings. In the absence of better curation tools for establishment means, this will make it even more onerous than it already is to make legitimately needed changes (for which I have used the tool occasionally in the past).
Maybe we could disable the tool for now, and if/when a “Senior Curator” category is established, make it available to just that group, with some explicit education to go with?
If that is done, the tool should also be made smarter. Besides the error check mentioned above for applying Introduced status, applying Native status to descendant places should only affect existing Unknown statuses, and should throw an error if an Endemic status is encountered down the chain. Descendant Introduced status should be left alone.