Digital Preservation Researchers - Disappearing Official Communications

We urgently need to start talking about official communications (and journalism!) disappearing from the internet. I'm working on a story about a specific event that happened about 15 years ago. The South African government put out press releases about it. By coincidence, I also wrote stories about it. Both are no longer on the internet. It is as if the event never happened. Great swathes of history – and evidence – are just disappearing. Are you a researcher working in this area? Want to chat to me about it? PS. Yes, I used the usual ways of looking way back to find them. Na da.