They won't necessarily be romantic routes, but there is indeed more content coming.
Eris/Raphael's route will be added to the main game, whereas Meara will be one of the routes in Sable's Grimoire 2 instead.
There's a rough timeline of when I expect things to be done here: https://steamcommunity.com/app/717850/discussions/0/1743392703799623229/