There are blockchakn projects that supposedly has it on their roadmaps to make it more decentralized like namecoin for domains and storage systems like storj or siacoin. Or theres filecoin storage that will serve as server.
I don't see why not... It won't be an easy task tough...
Who can push data? If everybody could create a new report and add it to the blockchain, it'll be spammed to hell...
If you'd use some kind of POW algo to require some work from data submitters you'll limit some whissleblowers while still getting spammed (but less than if you'd require no work to "mine" a block)...
If you'd require a valid signature to submit data, it cannot be submitted anonymously...
And i'd be afraid of some governements making it illegal to run a node... I can think off a few that would probably give harsh prison sentences to people hosting sensitive information.
It can also be used to misinform instead. Data submitters can be manipulated too. When a group of political rebels has agenda to push, it wont matter how expensive it can be in setting up nodes.