Since iNat doesn’t contain outside data (much of which isn’t even digitized for some groups of taxa), it’s not really possible for it to automatically identify new distribution records. There is an existing feature though the place checklists, which records the first time an observation was recorded in that area. There is also a comments and description section where additional notes can be made for observations of note like this. But I don’t think it’s a very high traffic part of the site, and anyone can edit the section, for better or worse. (if I’m misinterpreting your request, just let me know)
If you mean something new to iNat in a certain place (not necessarily an expansion of our collective knowledge, just what’s on iNat), there’s an existing request here https://forum.inaturalist.org/t/add-a-new-to-inat-species-discovery-counter-to-user-profiles/1545