This is a side project done only by Kal when he isn't working on RS; there's no roadmap because there's really non. If we would make a roadmap for things that are not set in stone, then people would complain when the idea changes or if it's not implemented, just like the complains about the farmlands not being part of 1.6. On the bugs side, we answer from time to time if is something known and that if it is something that will be worked on, there's a bug channel on the discord and that is managed constantly.
Requests are taken into consideration but ultimately is decided if it will be done or not, but not how until the update that will feature it comes near. Major parts of the update are what's advised here on itch, just like the post says, the major focus this time is: The new Harbor zone, and the characters that will be receiving more amount of content outside of Anna are: Emma, Frost, and Astrid.