Windows is back on ARM in the form of Microsoft Surface Pro X:
Unlike previous ports of Windows on ARM, this time they include emulation for x86 applications, like Rosetta 2 for macOS. This means that the existing ThinLinc client should be possible to use.
However, this support could be removed in the future, and it will have some overhead. Which means that a native client for these devices is interesting.
Windows 10 for ARM only supports 32-bit x86 applications. It is unclear if our installer will choose correctly here. But Windows 11 for ARM also supports 64-bit x86 applications.
We've done a quick test with Windows 11 for ARM here and the installer and client seems to work correctly. We have not tested that all features work, though.
As you point out, support for the emulation could be removed at any time (it is Microsoft, after all). One of the reasons I thought that "just use Rosetta" was the wrong answer when M1 Macs hit the market is that we know Apple *will* remove support for Rosetta at some point in the future, just as they did after the PPC->Intel transition.
I don't understand Cendio's refusal to acknowledge that an ARM-based client is necessary for Mac users and soon for some Windows users as well. Emulation is a less-than-optimal, but convenient, transitional tool but it is not a long-term solution. I understand that developing such a client takes resources and those resources cost money, but that's a cost of doing business if you want to stay relevant as the technology and industry evolves.