If the 2014 "Cherokee" (LMAO!) is any indication, Fiat hasn't the first clue what makes a up a Jeep. The"Cherokee" (LMAO!) is actually based upon a Euro market Alfa Romeo platform that Fiat has force-fit into the Jeep lineup. Expect something similar for the JK replacement.
As for the thought that people will just swap in solid axles, all that assumes the powertrain will be similar to what's in JK. If the thing is, as we suspect it will be, based upon a FWD car platform, or utilizes a FWD powertrain, then a solid axle swap will be out of the question.
Fiat displayed a 2014 "Cherokee" (LMAO!) at last Spring's Easter Jeep Safari in Moab. It got virtually 100% negative comments from the visitors who saw it, to the point that by the end of the event Chrysler's reps wouldn't stand near it. One told me what it was based upon and that Fiat had basically told the Jeep engineers & marketing people "This is it, make it happen". The absurdity continued with Jeepers Jamboree staff attempting to get them through the Rubicon. Photos of the helpless POS's looking like Aunt Millies Subaru standing on end went viral. "Cherokee" (LMAO!) will signal the end of the Jeep brand as we always knew it. Don't sell your JK.
'09 JKRU. 4" Teraflex long arm, Teraflex R44 housing, Teraflex / Fox Resis, Poly Performance skids, Nemesis Billy Rockers, Nemesis flares, 37" ATZ P3s on 17" 5x5.5" Trailready HDs, Spyntec hubs, Teraflex BBK, Mopar BBK master/booster, Superior front & Alloy USA rear axle shafts, CTMs, Reids, Synergy drag link & tie rod, WTOR hydro-boosted steering, 5.38s, TF Dual Rate front bar, TF bumpers, Warn Powerplant, Tom Woods shafts, AA xfer case cable, Kilby canister relo, RH4x4 cage.