Two watersheds that could occur in macOS 15: that it only supports Macs with Apple chips including an Arm processor, and that it opens access to older versions of macOS on Apple silicon.
Intel
The big question for WWDC is how Apple is going to put more distance between features for Intel and Apple silicon Macs? Here are some suggestions.
Help has been in steady decline since macOS 10.13. More recently, when you open a Help book on an Intel Mac it may get buried, but it doesn’t on M-series Macs. Why?
Why an Intel Mac’s up to 40 Gb/s from Thunderbolt 3 is less than an Apple silicon Mac’s up to 40 Gb/s from USB4, and how you can benefit from it.
There’s a problem with your Mac, so you try starting it up in Recovery. But that doesn’t work. What should try next? Intel and Apple silicon Macs are then quite different.
How have the CPUs in our Macs become faster since the Macintosh 128K was launched by Steve Jobs forty years ago?
From Hypervisor APIs in OS X 10.10 Yosemite in 2014, through early VirtIO kernel extensions in Mojave in 2018, and Arm hypervisor support in Big Sur.
Comparison between 2 Intel and 2 Apple silicon Macs running vector and matrix functions from Apple’s Accelerate library. Was that new M3 worth the money?
No updates for Intel Macs without T2 chips, apart from the iMac19,1, and there only in Sonoma. T2 and Apple silicon models are more confusing, though.
Three years and four major versions of macOS later, are Apple silicon Macs diverging from Intel models? It might look like it.
The Eclectic Light Company 