Atmas.

[Reynhart]

You think they are adding 6 new trials in a .05 patch?

Fighting a big monster is not restricted to "trials", they could be solo fights that you pop, like in job quests.
Or, it could have been too long to add 6 new trials to 3.1, explaining why Anima weapons have been pushed back to 3.15.

I'm not saying that there's no chance we'll end with an Atma type grind, but claiming that this is definitive proof is a bit early.

What would be very ironic, though, is for the first step to be an Atmas grind worse that the initial one, and that having the Zeta finished was suddenly praised by all the people feeling that their dedication was rewarded. The same people that felt so screwed when 3.0 gave better weapons, and denied the "Zeta owner will have a head start on the next Relic" as legitimate counterpart.