So the first thing I did was go through all the buildings/talk to everyone in raven rock. Everyone is talking about how raven rock is suffering due to the shortage of ebony in ravenrock mine. I completed the ravenrock mine quest shortly after, then I have the option of asking people "how things are going since the mine is back in business". This is where I got confused, how did the mine just start producing ebony again and suddenly people in the town are "doing great ever since it opened back up"?, was the mine closed?

Did I miss something?

Yup.East Empire.

I thought that was kind of sudden also. The mine was 'dried up' and nothing I did in the mine actually found some more ore, so I have no idea why all the sudden it's producing again.