If we broadly consider tanks as melee jobs and healers as ranged jobs, SE has consistently given us one of each type with every expansion. Even looking back at Heavensward, which had two ranged jobs, the job that came before was Ninja, and before that, Summoner. So in a sense, they've been alternating ever since ARR. Looking at those two categories, we've gone the longest without a new tank and a new magical ranged DPS. Anticipating one of each for 7.0 would be a safe bet, though it is worth noting that they may consider releasing two DPS jobs again. There was backlash last time they did that, but if they were to try again, now would be the time to do so while tanks and healers are "evenly distributed." Whether we get a new tank or a new melee DPS feels like a toss up, but a new magical ranged DPS should be a near certainty.

I believe SE has given us some hints that point towards what could be the next caster. It's a job that SE has spoken about before. One that they originally wanted to release back in Stormblood, but didn't due to the demand for Red Mage. It was a far eastern mage, referred to as Mystic or Onmyoji. The job makes an appearance during the Bozja questline and was also involved in the 2022 Heavensturn event. There is also The Heroes' Gauntlet. Within that dungeon, each boss is associated with a job that (realistically) likely won't appear in as a job for players in FFXIV. Meanwhile, all standard enemies are named after existing jobs already found within the game... with one exception: Spectral Ink Mage. A very curious inclusion. It sounds like a placeholder name for something else, and it wouldn't be a stretch to draw a connection between that particular enemy and Onmyoji when you consider that we've seen a shikigami summoned from a painting during the previous Heavensturn event. What the job ultimately ends up being called remains to be seen, but considering SE has already expressed interest in the idea, this job seems very likely to appear in the near future.

Personally, I'll continue to hope for Puppetmaster as a magical ranged job with the puppet as its main weapon much like Lulu from FFX.

As for what the next tank could be, one could make an argument for Beastmaster, considering the job has appeared equipped with an axe and a shield. But unfortunately, I suspect that SE is more comfortable with adding non-pet-oriented jobs. In which case, there is another option for a tank that would fill a niche that is currently missing. Rune Knight (or Mystic Knight). Tanks are missing a job that utilizes elemental magic to a meaningful degree. Rune Knight could attract players who would like to play as a spell casting tank that isn't focused on light or dark elements.

Regarding the next melee job, all signs point to a job that will share Scouting gear with Ninja, but what that job will be is currently a mystery. I can see a double-bladed sword user (like Zidane from FFIX) fitting into this role quite nicely. I see this inclusion being similar to Gunbreaker where the weapon is the selling point over the name of the job itself. There are several directions they could choose, though I'm personally fond of the Nightblade concept. It's a job that has appeared in Final Fantasy before, though not a common one. In the Mana series, it has ties to Ninja and Thief, making it appropriate as another Scouting job. In Brave Exvius, it uses debuffing slash attacks which is noteworthy when you consider that all of Zidane's weapons could apply negative status effects to enemies. I question whether SE would be willing to add a new DoT-based job, but at least there is a thematic similarity here.