Kinda late, I know. Still this is pretty exciting news.
https://www.youtube.com/watch?v=UMce5zh-_Rw
So, Rune Factory 5 is confirmed for a 2020 release and there will be a remake of Rune Factory 4 called Rune Factory 4 Special coming out this year.
Both of them will be on the Nintendo Switch.
https://twinfinite.net/2019/04/rune-factory-5-4-gameplay/