The popular Dehaze Function is released to the Creative Cloud Version, Lightroom CC. Since Lightroom 6 is the standalone version, new features in minor releases are shipped only with the next standalone major release Ligthroom 7.
When receiving minor release updates for Lightroom 6, the sources are installed anyway when updating to the latest minor release but the user interface does not offer the dehaze module.
To use this function anyway, follow these steps by integrating Dehaze not as a module but as custom presets defined in your installation: