This is not a bug report but is meant as a suggestion.
First: Every new building in this mission is introduced by it's own objective; even the oxen breeding the player knows from the previous mission, has it's own objective. Yet neither the micro brewery nor the brewery get mentioned anywhere. I don't think this is ok the way it is. Since they play an important role, it would be reasonable to introduce them, too. Perhaps combine it with the warehouse objective?
Second: Also the mine enhancing that is mentioned briefly in the text could well use an own objective, so that it can be reread in the objectives window. For WL newbies it can be rather confusing otherwise.
Third: Why not leave the "explore further" active until the "Boldreth shouts out!" event is triggered? Otherwise it can happen that the player has no remaining objective and - confused by so much new economic systems (deeper mining, soldier training, ...) - forgets what he is meant to do. It would also be just a very simple change.
Second: This is actually covered briefly in barbarian tutorial two. However, I was surprised to learn this when I replayed it once, so I'm not sure if it is always triggered.
Third: Hm... sounds reasonable to me. Unless the map is completed, there should be at least one objective open.
More, slightly off-topic about the second: I have wondered for some time if we should have additional, shorter tutorials introducing some key aspects. Rather than a map with a longer story, just some pre-built bases where some specific thing should be done (like upgrading mines and producing weapons). I should probably file a separate report on this, but I haven't really decided on what I think is the best approach yet, especially now that the introduction replaces/duplicates some parts of the first campaign maps.