If only they had localized Wizardry 8 in Japan, we might've seen some other developer try that style. It's mingblowing that no one since has tried anything like it. We need a wizardry 9 kickstarter so bad.
JPG style discrete combat screens with menu driven combat simply don't have much potential.
But they've managed to push that potential to its limits in Nocturne, which itself is a much higher standard as far as tactical complexity/ability to use varied tactics and difficulty are concerned than majority of RPG combat systems, including many TB games that do feature movement. Though obviously the next nessecary evolutionary step is a move towards SRPGs (ie adding movement to the menu driven combat), as Devil Survivor games had even more depth.
I guess you could still improve Nocturne's battle system with front and back rows (and have limited ranged in some abilities like in Soul hackers), maybe adding different attack types and more Wizardry 7 style exploration, since it already did feature some C&C. It might be a bit gimmicky, but if they were to make another game with 3+3 battle formation, then different demon types and alignments getting bonuses/negative modifiers for standing next to each other is another way to add more depth to the blobber formula. Kind of like getting extra attacks when you only had light/neutral/chaotic aligned demons in your party in Strange Journey. Chrono Trigger type team attacks between demons could be another possibility. Though when you stack power ups like that, then bosses would need to be tuned for optimal parties exploiting all the extra hits and power, because otherwise you could steamroll over them. That's the thing about having 2 rows of characters like in Soul Hackers (and having a large party in general): actually limiting the amount of characters the player controls is often good for depth because it means you have to make more hard sacrifices between choosing different characters with different abilities and spells, those SMT games being prime examples of that. DeSu>Nocturne>SH in terms of depth (SH is also a lot easier than those 2). You have to plan your routes, teams and spell load outs very meticolously before each battle in DeSu and study each individual enemy units spell weakenesses, strengths&spells/abilities (and which abilities can be skill cracked from them) and modify your teams accordingly.
Speaking of encounters, with more open-endedness there comes the question of balance, not in the JSE sense, but in the sense that are boss fights challenging enough if there aren't any mandatory roadblocks. Though the game did feature a lot of optional bosses and there was no equipment and slow stat development (1 stat/level, where as power creep is much greater in many other JRPGs) so grinding didn't help to overcome bosses nearly as much as in other games. They'd just need to figure out how to remove fusion level limits with out giving the player the ability to summon OP demons too early in the game, so that there would be no need to grind levels just to get some demons to encounter a boss.
Now that I think about it, there's definitely stilll potential left unexplored in the blobber genre (even in the pre-Wiz 8 style) that both JRPGs and CRPGs could try to tap into. Even though movement and everything that comes with it (LOS, terrain, Disgaea style puzzle stuff, interactivity with the environment D:OS style, backstabbing, formations, scouting, kiting etc), it is still nice to see new dungeon crawlers released as well. It breaks the monotony. Ditto for first person view action RPGs. As long isometric games with turn based combat, party creation and potentially some kind of AP system are the norm for CRPGs, all is good.