While it's possible they'll talk a bit about it, I think next week is still going to be focused on new content, rather than updated content. As far as I remember the time where they really talked about the old classes in SB was during the ~may live letter, where they showed some of the new skills for some classes(Foul, PLD wings and such, don't think every class had something though cause some classes didn't get new flashy skills like say MNK and WHM) and they showed some job gauge stuff and so on.
Honestly I wouldn't expect too much in terms of stuff like that, although DRK being a rework might be an exception, but I think it's more likely they'll focus on footage for Gunbreaker, reveal of the new class, talk about the story stuff to hype the 2nd MSQ part, show maybe the other primal, talk about the 8man raid and maybe reveal some other features in more details.
And you have to GCD Grit iirc, just you can remove it without a GCD since there's no DPS stance, just "no tank stance". So it's good for the pull threat where you start in Grit then drop it, but if you want to switch to Grit halfway into a pull(healer falling behind heavily on trash or DPS sucking so you're running out of cooldowns for example, or some dickhead SAM not using Diversion with better gear so you have to switch up) you're kinda fucked also. It'll be interesting where they go with tanks and their stances for sure though, since they've been trying to force tank stances in various ways but it never works for endgame content meanwhile it creates issues for casual content where either people who don't understand it don't use tank stance and fuck it up for everyone, or people would rather just tank stance everything and that then slows down kills, slightly fucking it up for everyone(but less than bad tanks in DPS stance however more common).
