I'd love to see an actual hardware description of the 2019 Fantom series and Jupiter-X (as well as my Fantom-G), but what I reckon is this : These modern keyboards are computers with a light (usually linux-based) real-time operating system and a proprietary software on top (whether it's got a color touchpad, lcd, an OLED or no display is secondary)).
They might be paired with dedicated micro-controllers to manage I/O, dedicated knob, sliders and other interface peculiarities; they may even use dedicated chipset (FPGA) for timely and efficient DSP work, still, they are computers with a bunch of soundcards. RAM aside (no longer a real problem), it all goes down to CPU(s) power, and since they favor fanless ones (not the fastest, but no noise and no fan failure expected...) and as minor buyers have no leverage over their specs and foundry, they shop just like anyone else at Intel, AMD, Qualcomm etc. Then they make whatever they chose in the space they're offered with.
As a Corporation, they chose to favor profits over service. That's simply called a commercial policy. As sure as they leverage their common "Zen-core" (PCM) technology and overall architecture over their product range (think MC 101 and 707 as well), they surely could just swap V-Piano and a JP-8 model between Fantom and JP-X, but they won't. Unless they discontinue the JP-X because it'd be a marketing failure in the end (just look at the price tag !), and make it availlable for free to the fantom community, they won't - at least intially - make their ABM synths availlable for the fantoms because JP-X Owners would feel s.....d-up.
But if they chose to sacrifice the JP-X to give a commercial boost to the fantom (name it fantom-Y and paint it white), then so it'll be ! Why selling only once the same thing while you can sell it thrice to some fanboy under three different color schemes ?
I might buy a F-7 at some point because I'm playing live, triggering samples etc. and it's half the weight of my G-8 and nearly as convenient (no multi-sampling though, and nothing close to ARX-03 for good Brass section articulation...), and in that respect, the VA-modelling (a legacy from the Integra-7/Jupiter-80/50 line ?) does the job okay over PA in a bar or that kind of noisy venue. But if you're looking for the analog glory for your studio production, look elsewhere, and maybe not even in the JP-X.
Frankly, I've never played on a true JP-8, but I guess a big step up would be moving faders when you go from sound to sound on a recreation, so that what you see is what you get (even though there would be more menu-digging through the OLED). You don't even have that on the JP-X : interface-wise it's no more advanced than my Gaia (the SH-01 is in fact a synth for learners retro-inspired by the no-nonsense JP-8 layout), and I'm not even sure sound-wise better than their Cloud service, or previous ACB machines (Cloud is probably the same code as ACB H/W : why coding twice ?). Any good VST for that matter (listen to the Moogy "Monarch" for instance) at least presents the actual state of the machine : a coherence between what you hear and see on the GUI.
On the Hardware side, Hydra-Synth seems to nail it, and sounds really interesting. Rather than a Behringer-8 clone, there probably lies the real JP-X killer, which is not a workstation, yet not a true analog, not a so straighforward machine to tweak, and still begging for your hard-earned money a GRAND more than the Hydra...
And appart from your own speakers from a true analog machine, all you hear is digital at some point, folks, nobody directly engraves an Vinyl or magnetizes a tape, there's at least a digital Master (AAD at best, remember on those old CDs ? DDD was the must then...)
