Ladies and Gentleman I give you Teras Kasi Artist.
The problem with Teras Kasi is, and always will be, that Teras Kasi is, pretty much by definition, an anti-Force fighting style. It's part of the history. The timeline of TOR, Teras Kasi would have been a freshly developed discipline and, as such, wouldn't have had the time to leak outside of the order, which was notoriously antagonistic towards the Jedi Council and, presumably, the Sith as well (since they didn't like the Force). It wouldn't make sense for a decided anti-Force combatant to willingly ally themselves with either faction since, in both cases, the respective Councils have a *lot* of authority.
SWG got away with it because Jedi were friggin' rare in the timeframe of the movie (so they wouldn't be a major concern), and we're talking about nearly 4 millenia of cultural evolution and individuals leaving the order while maintaining their skills to teach to people outside of the order. TOR takes place at pretty much the *height* of Jedi and Sith activity in the universe. A *lot* of the quests, not to mention the overt planet storylines, revolve around working for the Jedi in one way or another. How does that grok with someone that's been trained to believe that the Jedi are bad and that those who aren't Force sensitive, decked out in the fanciest of new military equipment, or just damned lucky need a way to fight back against them (the express purpose of the Teras Kasi meditation techniques was to close one's mind to the Force) lest they wreak havoc on unsuspecting innocent planets all over again?
This isn't to say that an unarmed combat class is completely without merit. There is an artefactual category of weapons called "Fist Weapons" buried in the code (found via datamining) so, at some point, it probably occurred to the developers to have them included. The problem is in finding a style of unarmed combat that already exists within the canon (since I doubt the developers want to create an entire class, including backstory and theme, from scratch) that works within the time frame (which is why Teras Kasi is out) while having equivalent options provided to both factions. Even then, you'd have to come up with a reason why the developers should actually put forth all of the effort to develop another class (which is the biggest issue, as I see it, since it involves writing and recording a *lot* of story and dialogue; the class design itself is relatively simple once you've done the creative work of coming up with a core mechanic and theme).
Even if you required the class be bought with Cartel Coins (which is the most likely way it would be implemented, though subscribers would likely get it automatically), you have to wonder how many people would spend the extra money on it if it performs on par with the other classes and simply provides a different aesthetic (at that point, you have to debate whether it's better to use as a marketing tool to get people to start playing the game or an actual product that some people wouldn't bother buying). This is probably the biggest hurdle since developing a new class represents more overall effort than pretty much any other potential endeavor in the game at the moment (barring completely new systems like the Super Secret Space Project or guild ships/planets/etc).
As to what I would do with an unarmed combat class, I would go with Echani, rather than Teras Kasi: it's a more appropriate combat style for the time (Echani was referenced in the original KotOR as well as being even more involved in KotOR 2) and (for the factions (since the Echani had no specific problem with Force users) and provides options for both unarmed combat (via gauntlet weapons) and armed combat (vibroblades), not to mention some kewl possibilities for a tree devoted to turning your existing vibroblade into anEchani Ritual Brand
for some interesting visuals and elemental damage. Of course, the biggest problem (as I see it) is coming up with a way that non-Echani would be involved since Echani is as much a species as it is a culture (whereas Mandalorians are a culture rather than a species), though I guess you could go with "adopted child" path to explain any racial discrepancies (still feels like a cop out though).
Of course, when doing any development for an unarmed fighting class, you have to ask yourself what purpose it fulfills that isn't already fulfilled by another class. Thematically, it would be a new addition, but, mechanically, you'd be adding a new way to DPS and potentially tank in light or medium armor in an acrobatic style which Sentinels and Shadows already do perfectly well (I really don't see Echani as being a healing class, unless it's something obscure and almost absurd like Acupuncture). Unless you also tack on a new and substantially different resource mechanism (which is the primary factor in differentiating classes) to go with the story, you're really just reselling Shadows and Sentinels with fist weapons instead.
All in all, I'm hoping for an unarmed combat class sometime in the future (not the near future, for sure), but I'm hesitant to actually think it might happen. There is just too much involved in developing them combined with some problems in world building and lore that just make it difficult. Even if there was a groundswell of support, I have to wonder if the developers would actually do it (though I would bet more than a few people would make commentary about TOR developing "monks" just to mimic WoW's).