Was the person calling himself John Titor, who claimed to be a military time traveler from the year 2036, actually genuine, a hoaxer, or a minion of the Extraterrestrial Alliance sent as part of a disinformation campaign related to Disclosure?

Unfortunately, the latter is the case. This was a planted body of information deliberately designed to introduce the idea of time travel in the context of potential human catastrophes, as a consequence of societal changes, and the direction of things to be expected for Earth itself. This individual was a member of the Mercenary Army Program sent back from the future to carry on a kind of charade with a carefully instilled script to follow, and close monitoring by extraterrestrial psychics to ensure he stayed on point and delivered the desired information effectively, and without leaving loose ends or making mistakes that could undermine acceptance and believability of his false narrative. As such, it proves nothing and adds little to the ongoing situation, it is one of many forays done to introduce confusion and complexity in the discourse but has had a minor impact on things.