It turns out things online don't exist forever. There are lots of things that are deleted and are impossible to find afterwards because somebody has to archive

It turns out things online don't exist forever. There are lots of things that are deleted and are impossible to find afterwards because somebody has to archive it and at some point that "somebody" stops caring. So when things like the service they used to host the content clear up old content, things don't get reuploaded. I really hope that these tweets are not only stored, but stored in a way that makes it difficult to prevent manipulation. I think many of Trump's tweets (and his family) are historic. Hopefully they're archived in a way that they last decades/centuries.