> Windows is available for ARM, and it supports emulation of x86 apps just like Rosetta.

Not really. It is a long way behind Rosetta.

(Partially because Apple only built the M1 to be optimised for running Mac apps in emulation, partially because Apple had spent five years deprecating older software very aggressively so nobody expected those things to work, partially because it's genuinely hard, and partially because it's not very good.)

It's not really readily available either, only a preview build.

The licensing concerns do play a factor. VMware also makes it difficult to run Mac OS VMs on Workstation for the same reason.

(Source: I recently left VMware)

I believe Parallels has chosen to ignore/sidestep the licensing issues by using the Windows Client ARM64 Insider Preview builds. We'll have to see what happens when the Insider Preview builds stop being produced.

The Insider program has offered continuous builds since 2014 when they moved to a regular release cadence so it's not likely this will change unless something drastic happens to the versioning in which case licensing models would also change anyways.

What the Insider ARM builds did give you that hasn't been in a release version (until tomorrow) was x86-64 emulation support and a few other minor ARM improvements and an easy way to source a compiled ISO directly from Microsoft.

As far as activating a standard Windows 10 license will activate Windows 10/11 for ARM even if the EULA says it won't and, regardless, switching to Insider builds doesn't sidestep licensing as you need to be licensed to join a PC to the program and the ISO installer has the same licensing and EULA requirements as a normal installer ISO.

This, I'm running Win Preview Arm64 + ArcGIS on an M1 Air through Parallels, no issues so far.

yes, but will it run CRYsis?