Presumably Tyrande, Malfurion, and crew have better things to do than stand around all day answering trivia questions.

Also, this should *add* to the confusion, not clear it up. If you don't believe me, ask a few different people at an accident scene what happened. Ask a few hundred people who lived through historical events what *really* happened.

Presumably powerful shamans capable of seeing what happened many thousands of years ago generally have better things to do, too. As well as people who can see the future. You mention such arcane rituals exist, and indeed they do, but we know they're not commonplace or there would be no such thing as a surprise attack in WoW. There would be no point in using stealth if everyone had true-sight. Etc. There are all kinds of magic that negate some of the ways things are hidden, whether by time, stealth, or magic, but they can't be universal without destroying the setting.

It would also contradict the lore, since it's established lore that stealth exists, despite the fact that magic exists to counter it, surprise attacks exist, despite the fact that magic exists to see the future, and questions about the past exist, despite the fact that magic exists to see the past. We know these things exist, but we also know they are *not* commonplace or easy.