This case is a cure. HIV is pretty well known to not go away on its own (except under the circumstances described in your link). This treatment is almost certainly responsible for him no longer having HIV.
The notion that a cure must be widely applicable in order to really be a cure is rapidly becoming obsolete: many hypothesized or developing treatments involving stem cells or genetics or bacteriophages are very specific, often to the level of needing to be manufactured/cultured/etc. on a per-patient basis. This makes them less useful, but really has nothing to do with their ability to actually work.
This case is not announcement that a miracle drug will be hitting pharmacies in a few decades, but it is proof (or at least, very strong evidence) that HIV can be defeated in vivo.