How progression is going to work is a little confusing to me here though. I like farm-sim like stardew valley, I like base/home building, but I'm not sure where the "objective" part is going to be here. I like building a base / home - because I can then use it as a base / home while I go to do things. Improving the base and the interiors in order to unlock something you need to get to the next location, or boss, or blah blah.
Building a home for the sake of building a home would still be fun... until I'm happy with the home I've built. Then the game would die for me unless there are objectives to do, or challenges to overcome. Usually building a solid base may take a day or so of gameplay at most, but MMO are usually intended to have a long lifespan and an active community.