Either way, the World Government has been lying to the entire world and is the current form of the Alliance that defeated this advanced civilization.
People will revolt if they don't get the actual truth of what happened from the Government.
Some will, and that's key with all these reaction shots we're getting. It drives home two crucial points:
1) This shit hits everything and everyone, everywhere. All the people we met, all the places we visited, all organizations that have been fleshed out over the years. It's not like a bounty upgrade or a shichibukai being defeated; everyone is 'targetted' by this news.
2) To show, well, their reactions. We have people believing Vegapunk, questioning Vegapunk, mocking Vegapunk but more crucially; we have that WITHIN the organizations. We have Celestial Dragons telling him to stfu, but then also that one shot of the lady CD shocked. We have Marines doubting, marines believing etc. etc. etc.
You simply cannot drive home the consequences of this news
without showing this. People might not like it, it might feel a bit dragged (I certainly don't blame you if you feel that way), but it's such a needed sequence.