URL shorteners can be a reliability problem because if/when they go down, it becomes impossible to figure out where they actually pointed. So, we should be proactive and offer dumps of our short URLs.
Providing a raw sql dump isn't going to be very useful because the PHP code does encoding and normalization of URLs at runtime. Also, ArchiveTeam/301works.org (link) use comma/pipe separated text files as dumps.
https://gerrit.wikimedia.org/r/#/c/248644/1 contains a maintenance script to generate a text file in that format. We would need to set up a cronjob for it, compress the result, and publish it somewhere.