Just downloaded my Twitter archive again and converted it to Markdown, including high-res images this time. I suggest you do the same if you want a backup of your data that is independent of Twitter’s servers and free from obfuscated t.co links.

Here’s a quick how-to:
https://matthiasott.com/notes/converting-your-twitter-archive-to-markdown

Converting Your Twitter Archive to Markdown · Matthias Ott – User Experience Designer

Matthias Ott is an independent user experience designer and developer from Stuttgart, Germany. Besides design practice he teaches Interface Prototyping at the Muthesius Academy of Fine Arts and Design, Kiel.

Matthias Ott – User Experience Designer
@matthiasott is the internet archive doing anything about t.co links.... it would be good if there was a way we could back them all up there.
@64kb That’d be great, yes! But I have no idea if they are doing something in this regard.