If we get a 2-handed sword class/job, I expect it'll be a tank rather than a DPS mainly because (1) we need tank class/jobs more than we need DPS and (2) there aren't that many tank-y weapons remaining.
Furthermore, "support DPS" isn't really a role. Support exists as a sub-role within the subset of primary role as, thus far, as only come into play as part of a job (likely to prevent too much of your class focus to devolve into helping other people out instead of actually making yourself stronger) and only provides intangibles, like TP and MP, rather than explicit improvements to damage or survivability (the closest you get to damage support is Selene, when she's providing 10% speed to a given Discipline half of the time, and that's only a ~4% increase to damage). Benefits like that (especially if they applied to all damage instead of a very small subset of damage like the Foe's Req, Storm's Eye, Disembowel, or Dragon Kick) would basically turn the class into an absolute "must have" (BRD doesn't even provide anything close to a constant global damage buff and is still often considered to be a "must have") unless it's native DPS is absolutely terrible (wherein it will be an absolute "never bring"). "Support" doesn't scale to group size because it's becomes way stronger in a large group than it does in a small group, which just has it cause even more problems (consider 2.0 WAR wherein IB was simply a self-heal without the DR: it was overpowered as hell in 4 man content and basically worthless in 8 man content; some stuffs just doesn't scale properly in different sized content; global damage buffs is one of those).
If we *were* to get another "support DPS", I expect it to follow the model of the BRD: a straight DPS that can reduce its own effectiveness temporarily to provide some useful non-damage benefit to the rest of the group.
Just because they're not explicitly *called* "Power Break" and "Armor Break" doesn't mean that they're not in game; they belong to MRD/WAR: Storm's Path is a 10% reduction in damage dealt by the target for 20 seconds and Storm's Eye is a 10% reduction in the target's slashing resistance (Disembowel is 10% to piercing, Dragon Kick is 10% to blunt). LNC/DRG's Feint (20% Slow for 10s) could easily be interpreted as "Speed Break".I found it odd that we didn't have Power Break and Armor Break, when they've become rather big things in Final Fantasy.
That's not going to happen because you'd have 2 jobs playing almost exactly like one another. Classes provide you with 17-18 abilities (including all of your fundamental ones like a vast majority of your standard attacks) and 11 traits; jobs provide you with 5 abilities total, most of which are going to be situational or supplemental. Unless the devs suddenly decide that they're fine with having 2 jobs play almost exactly like one another, we're never going to see 2 jobs with the same role coming off of the same class. If it were to have 2 jobs, expect 1 to be a tank and another to be a DPS, not 2 DPS.Now, after they hit 30 they can become one of 2 Jobs like the Arcanist. The difference is this time they're both DPS still, one of them turning into a Defensive Support and the other turns into more a more damage based form.
On top of that, the class would have to be explicitly built around having both roles' capabilities either present or easily included: SCH gets its baseline heal, almost all of its healing buffs (via Selene/Eos and Rouse), and its rez through ACN, which is a DPS class. Neither the baseline heal nor the rez are functions you'd expect to see as static capabilities of a DPS, so those abilities were placed there so as to make the conversion into a healer possible (and, even then, SCH has to wait until 50 to get the full suite of capabilities that a WHM basically gets by its mid-20s).
As a final point, Yoshi has said that they're only going to go to the effort to add class/jobs that are iconic to the series. While Cloud is definitely iconic, he's not really iconic to the series. A 2-handed sword class is much more likely to be something like Dark Knight or Mystic Knight, which have a much more significant and defined presence in the series than SOLDIER.