As usual the media will likely try to put its own spin on whatever the archives reveal. My biggest fear is that they will try to judge the Holy Father’s actions by the standards of today, not the standards of his time.
My guess also that there’s a huge quantity of material to sift through, and it will be difficult for outsiders to put things into their proper context as many documents are likely interdependent and cannot be properly interpreted in isolation, or outside of a timeline where an idea or thought is developed and evolves into something not even close to the original thought.
And as such, it risks descending into another bout of Church-bashing if the Vatican does not keep a proper control on the release of information.
Once the archives are opened, whatever the media is fed should be put into proper context by reputable scholars, perhaps even scholars approved by the Vatican to release the info to the public. Not necessarily all Catholic, but instead chosen for their reputation and objectivity.
It will be a long process, I hope to live long enough to see Pope Pius XII publicly vindicated!