Personally, what I'd really like to see is for AB to go back to the lyrical themes of The Last Hero, but really dig in and go full Rage Against The Machine on it (minus the rapping). I listen to stuff like Writing on the Wall which is clearly about Trump and the science/climate change deniers, or even the milder generic "make the world a better place" stuff like Rise Today, and I hear someone who's trying desperately to take a stand against those kinds of forces in our world, but is also trying to toe the line and keep things simple enough not to alienate any of the fanbase by being too "political." But I mean, at this point, I've seen full-blown QAnon conspiracy theorists who are still waving the AB flag, so I don't think they'd be in any danger of losing any fans over it.
Still, I feel like the chances of that actually happening fall somewhere between "Stapp joins the band" and "Flip does a solo album full of funk and disco covers" (which, let's be honest, would be dope as hell), so other things I'd like to see them do... these guys really shine when they strip it down and play acoustic, so I'd love to see a full-on acoustic show DVD akin to Sevendust's Southside Double-Wide. I keep a playlist going on YouTube of all the best pro-shot acoustic versions of things I can find, and I pull that up every so often to listen to it like a standalone album, and it's just wonderful.
Aside from acoustic, the other place these guys really shine is doing covers. I think a covers album / EP / set of EPs could do them wonders, especially if they were to do something that's already a big mainstream song the way Bad Wolves hit with Zombie a couple years ago. Back on the ODR tour, their propensity for covers was amazing, Zeppelin, The Who, Aerosmith, they played that stuff just flawlessly and having them get into the studio and put those songs out there for realsies? Would be incredible to hear. That video of them doing Kashmir at Pinkpop has blown my mind countless times over the last decade or so, and I think they could tear it up on some stuff like that and really turn some heads.
I think their next studio album is just going to be what it's going to be, whatever they feel is right, whatever the next evolution of AB is. But especially with things on Covid lockdown, I think this would be a time to just hop in the studio and crank out some of this kind of stuff. Especially the covers, they could put those out there with hardly any effort and reap maximum benefit.