There's something poetic about abusing a link shortener as a database and then later having to retrieve all your precious links from random corners of the internet because you've lost the original reference.
The real abusers are the people who use a shortener to hide scam/spam/illegal websites behind a common domain and post it everywhere.
In other words, every shortened url is "using the url shortener as a database" in that sense. Taking a url with a long query parameter and using a url shortener to shorten it does not constitute "abusing a link shortener as a database."
It’s simply a normal use-case for a url shortener. A long url, usually because of some very large query parameter, which gets mapped to a short one.