Those are the best we have, which is why they made the news, but nobody can draw any conclusions about what the images are. We are back to the same place, fuzzy images that don't tell us much, some kinda looked like balloons to me. Perhaps they are remnants of burst balloons, whose payloads have dropped away, but some gas remains trapped in part of the envelope and it floats around like a plastic shopping bag in the wind. However some of the reported phenomena do not fall into this category, but further investigation is not possible, until the next one shows up.
As for the government keeping it secret, not possible for something like this, national security is one thing, but this is another thing all together.