No, we won't. We don't even need them for current savage. You can clear ultimates on a Playstation (and soon Xbox).

They are not going to get harder in the way you are suggesting either. If they get any harder, they are probably just referring to something like Heavensward or Stormblood, or easing up on the degree of telegraphing. If we're honest, there's probably nothing they can do to a dungeon that's going to make it much more challenging to a veteran player with years of /playtime, but they can make it more varied or threatening.

The only argument you can make for needing to track DPS is if there is an enrage, which I don't think there ever will be in a dungeon. And even in that scenario, you don't need to track DPS because if you wipe to enrage, then you have your answer: your DPS needs to be better.

Also doing good DPS scales with doing your rotation properly, optimizing for potency-per-second, mechanics and phase transitions, not letting cooldowns lapse unless it's to align with lots of raid buffs and gear, materia, food and damage potions. If you just do all that then you're never going to need to calculate your damage.

Now it does make DPS more accountable in the sense that you can look at someone else's damage and then attack them for doing their rotation completely wrong or still being in dungeon gear. But that is exactly why they aren't in the game, because that is the culture it creates.

You can usually spot who is not playing well by their ability to do mechanics and their HP being lower than average (indicating lower gear). If it was a static you would be able to just test them in a variety of content to see if they are playing well. You can see who is pulling their weight in dungeons for example and the best DPS usually has second enmity.