Seems like you identified a missing aspect, that could be beneficial to the threadiverse.
Although, I'm not sure this makes the most sense as a feature, but should rather be a specific community. I think it would fit in quite nicely with the other community building communities:
- !newcommunities@lemmy.world (announce)
- !communitypromo@lemmy.ca (promote)
- !lemmy411@lemmy.ca (user discussion)
- !fedigrow@lemmy.zip (mod discussion)
Now with: SuggestACommunity@instance (ideas)?
Maybe another community or a running stickied post, with people volunteering to potentially mod certain types of communities. Comment example in such a stickied post: "I'm potentially willing to mod a history or data analysis community".
If a post suggesting a community that matches the potential mod's criteria comes up, they can be tagged/pinged in the post so they know to come check out the post and see if they want to mod the suggested new community.