I'm sure if Apple provided support for installing your own OS on their M series laptops it would be incredibly popular. And I don't need to guess at this using weird 1996 research on microkernels because Asahi Linux exists and clearly there is interest in it.
We don't need research because QNX, L4 and many others on embedded space do exist as well.
Apple was not a bastion of quality in the 90's. They couldn't modernize the Mac OS, and that continued with little more than window dressing over what was released in the 80's. The Mac line up was a horrible mess of barely different models that needed a Ph.D to figure out what was different. The company was bleeding money and seriously close to bankruptcy.
The Apple of the mid 90's wishes it could release something like Tahoe.
OS 8 was a platinum theme over System 7. Which was a slightly better System 6, which wasn't significantly different than System 4.
System 7 was good for the time, OS 8 and 9 were not, and Apples inability to improve the OS were really starting to show. Windows 95 was a more stable OS than OS 8. Tahoe is better.
Not to mention that the OS itself was still mostly 68K emulated code even on PPC Macs and holding the mouse down over the menu caused all apps to stop running.