If I reset the map instead of keep it does it reload to previous versions or completely wipe it?
To answer the title, it resets everything, is like creating a new world but without the hassle of selecting the mods/options.
the second question, the loaded game always run with the current version installed, so no, it doesnt reset your version
Keep in mind that (at least in my experience this is the case) excess use of the reset button eventually starts generating rather weird worlds that don’t exactly match the selected world options.
That is false until proven to be true.
I believe you are correct. After testing it in a vanilla world with default settings I no longer get problems with worldgen. Either one of my mods has a problem or I have a problem with confirmation bias. Either way you can safely disregard my former comment.