Pre-release versions are created to test new updates on bunch of different hardware setups (OS/GPUs) before releasing more broadly (and making new versions the default for the Linux/macOS/Windows installers – those pull from the 'latest' release).

There are a good number of folks that test the pre-releases as well (thank you!) especially if there's a bug fix or new feature they are waiting for. "Watch"ing the repo on GitHub will send emails/notifications of new pre-release versions