And if it were done like this, how would THF and NIN be any different? They're both DPS classes, and support and DPS are *not* separate roles, which you seem to suffer under the delusion of (support is a secondary functionality that any class can bring). Unless you expect one of them to be a tank or a healer (which is laughable for either of them), they're not going to both be jobs based off of the same class because it is monumentally redundant to have 2 jobs with the same role coming off of the same class.
On top of all of this, how would all of the monetary/gear and out-of-combat utility that THF brings be in any way incorporated into the class itself? Any ability to generate gil out of nowhere would either be worthless or screw up the economy, especially given how little gil you make by running DoW/DoM classes. You could *never* have them stealing items since that would be broken as hell. Managing party enmity is largely pointless given how much enmity WAR and PLD already generate *and they're only making it better*.
The only iconic thing that you can say that a THF would get in ARR is backstabbing and maybe some evasion; the closest you could get to making Steal a useful mechanic is by making it a resource mechanic like Aetherflow. It's a bare bones DPS construct as far as an MMO is concerned. THF could only exist on par with classes like NIN in a single player game because the things that made it effective and unique *could actually exist in those game as abilities that made them useful* (though you still have to remember that they always had tier 1 job/class stats; the higher tier jobs *always* had better stats so the *only* thing going for Thief was that they were the only class that brought Steal, which is arguably the most useful skill in the game).
Is it also a hint that they plan on removing LNC and PGL because they didn't include them? It's *way* more likely that the reason is because they're copying the encounter model from 1.0, which has a completely different class construct than ARR.The ARC is wearing iconic RNG gear. This could be a hint that they will be making BRD a more support oriented job and bringing RNG as ARC's DPS option.
As far as the entire FF series is concerned, Archer and Ranger are the exact same class. There isn't a single game that has Archer that has Ranger in it nor is there a class with Ranger in it that has Archer. They're both just the bow/crossbow using class *and that's it*. Saying that they're going to change an existing job that works *quite* well to completely change it focus to something that doesn't even exist within the game's actual combat model and provide a *new* job that makes the previous one redundant fails on *so* many levels. BRD already deals DPS just as well as the other DPS classes. Support is simply a secondary functionality that it brings while also being a fully functional DPS (you'll also note that they lose DPS by providing the support, which is the balancing factor behind that capability; constant "support" simply doesn't happen because it doesn't work in a balanced way that is constantly useful).