"Developer preview" means we're still going through internal testing processes. The code review is still in progress (the windows port hasn't been merged into next yet), and the build hasn't been widely tested in the wild.
Everything seems stable and there aren't major known bugs, but there is still work to do before we can label the windows port production ready.
A developer preview is a prerelease of a user software package that's potentially a platform for other software, targeted for developers who would potentially build applications for the package's user base. An OS like windows may have development previews, as tgerr would be developers who would want to start early to develop apps on tge platform. Sublime text may release a development preview in order to allow developers of plugins to start early to update thir plugins to the new version. But a database is not a user application, it is a developer's tool or a component of an application. Thus a developer preview of a thing that will never directly face a user is not logical. You want to say release candidate or simply beta instead. Developer preview implies extensible user application.
edit: speling