Yes, because Telltale only has to snap their fingers to have the game on Xbox, and the only reason they're not doing it is because of a personal hate against Xbox users.
Porting a game to another console requires work. They need to adapt the Xbox portion of their engine, since like you said, only older games are released on that console, and the Telltale Tool has advanced for ToMI. They're already swamped with other projects, they've got Sam & Max Season 3 going on, Puzzle Agent is coming out in a couple of weeks, and they're working on the two new Universal games, not to mention the secret projects they're undoubtedly working on.
Since Telltale has stated over and over again their aim is to get their games on as much platforms as possible, it's pretty likely ToMI will get ported to the Xbox. But it'll take a bit of patience on your side, and not random, unfounded accusations.