This is likely at least partially driven by a desire to stop maintaining Intel versions of macOS. Apple tends to keep the list of supported hardware short anyw

This is likely at least partially driven by a desire to stop maintaining Intel versions of macOS. Apple tends to keep the list of supported hardware short anyway, but there’s added incentive with the architecture change — Intel macs are missing several things that are present in M-series macs, which means that they can’t write updates assuming those features are present, which naturally complicates things. There was a bit of this with the PowerPC → Intel transition too, though I’d argue that change wasn’t nearly as dramatic, with the main difference being increased clock speeds and core counts. M-series is more significantly different from Intel (and x86 as a whole) overall than Intel/x86 was from PPC. I suspect that the first release of macOS where Intel support is out of the picture entirely (or restricted only to 2019 Mac Pro towers with an M-series accelerator card installed) will also bring the most radical set of changes shipped in a macOS update in a long, long time since they’ll be able to make those aforementioned assumptions. Does this justify cut back support timelines? Probably not, but it tracks with Apple’s typical mode of operation.