Original brith and death locations for Gertrude Svensdotter were listed as "New Sweden, Aroostook, ME, USA" which is incorrect. The New Sweden colony in Maine was established in 1870. This New Sweden was established in 1638 on the Delaware River.
https://en.wikipedia.org/wiki/New_Sweden
https://en.wikipedia.org/wiki/New_Sweden,_Maine
I would like to add the correct location, but it doesn't exist anymore.
Correcting what?
That people don't bother entering location details themselves?
The automatic look-up is just a helper feature you have a choice to use or not.
When entering a location _you have a choice_: enter whatever you want in the detailed location fields where there is absolutely no automatic look-up (but you might have configured your own browser to come with suggestions on previous values you have used, but don't blame Geni for that), or use the simple location field and rely on wheat you get there,
If you want the automatic look-up corrected to include historical names you should direct that complaint to Google. In Google map you also have an option to make corrections.
When entering names that are ambiguous, and where Google Maps knows only one of the alternatives, there's no way around using the "Edit Location" details.
And the only way to make sure someone doesn't enter the wrong one by misunderstanding later is to put your source into the entry - either in the About Me or under Sources. That way, it can be verified later.