New features added after you paid the upgrade price to the next full numerical version are usually held back until the next paid upgrade to the next full numerical version. Features like dehaze fall into that category and are only available to subscribers with there decimal releases. If you continue to hold a perpetual license, You would have to wait and buy an LR7 upgrade to get any features added since LR6.0
That said, the functionality of the dehaze is included in the develop engine. The only thing missing in=s the user interface to access those dehaze functions. Since the functionality is in the code, some industrious folks have developed plugins to access these and get around the missing user interface.
The current update is LR6.4 which has added new panorama functionality. I have not heard whether this new functionality is available to users that have purchased a perpetual license.
