I just noticed that my user talk page in the Catalan Wikipedia was converted to Flow. Thanks to whoever did it (@DannyH?).
There's an issue, however: It's in a category that has a French name: "Page de discussion fonctionnant avec Flow". I'm not sure where does it come from; such a message doesn't seem to appear in the Flow codebase.
And while writing this bug report I noticed that the same happened on my Hebrew Wikipedia user talk page, too.
There must be a French category name lurking in some conversion script or configuration file, but I don't know where to look for it.