I think the 8600 and 9600 were finalized and on sale to customers prior to Jobs' re-arrival. It was probably just done in haste, but it's tough to tell where planning for, say, the next gen after the 7300-7600/8600/9600 was at.
Apple had started cleaning its own house just a little bit in 1996 and 1997 prior to the NeXT acquihire. Newton, QuickTake, ISDN stuff, video conferencing stuff, some Claris stuff, some other OS projects, some CPU projects, and a few things like that got killed. Printers, Scanners, re-badging low end displays. I'm probably missing a few entire corporations' worth of stuff. In addition to Apple trying to be everything to everybody the Mac lineup, they were pretty much trying to get into every business.
I do agree that it's very interesting that the 8500/9500 got custom cases and the 8600/9600 didn't. Maybe the mechanism was so involved it would have cost too much to design twice? (ignore that the beige G3 ultimately shipped in the proportions that would have been appropriate for the 8600...).
Yeah, I mean, if what
@Syntho wants is 5.25-inch floppies, the answer is
functionally an "outright no" on a PowerMac unless you can get the people who designed the xpanse, system 7, the 9600, and the nubus 5.25 dos drive interface all in a room to cogently develop new software or drivers.
All those things will connect but I think you're right, the drivers and interface software won't play nice on PowerPC. They may not even play nice on system 7, but I don't have the docs in front of me.
If I remember correctly, the way Apple's 5.25 interfaces for the SE and the II worked is that you'd pop a disk in, fire up the disk translator app and browse through it similar to if you were connected to an FTP server, then bring data over. Apple never set up those mechanisms to work with Mac data or be used directly in the OS. The same is even more true of the IIe LCPDS card. As far as I know you Can Not access that 5.25 drive from the mac, even for like imaging or data conversion.