With plug and play distros like Pop_OS! and built in drivers for Nvidia GPUs, i think this is relevant for consideration. Yes, the percentage of Linux users is small, but the percentage of Fusion 360 users is even smaller. One of the main things keeping people from moving from Windows to Linux is the absence of a few programs like Office, Adobe suite AND the CAD programs. I bet you would see quite a few people run Fusion 360 on Linux, if you tried to do it. And you only have to support a few main distros - or maybe only Debian (with all its children). The desktop does not really matter so support should not be a nightmare. I have used both Windows, Mac and Linux for decades. They all have pros and cons. But Linux will grow with the bloat of Windows and especially with Windows 11 just released and you'd probably have a much sounder OS for Fusion 360 professional use than Windows is. What about an experiment? Build an alpha version for Linux and get insiders to try it out?
For me, only three things holds me back from using Linux for my daily driver: Lack of Office, Ableton Live and Fusion 360. Office runs find in a Window VM under Linux, so that is not holding me back. But lack of proper GPU passthrough to Windows VM, makes this solution impossible for Fusion 360 and the same with Ableton Live (music production software). There are good alternatives there, if I'm willing to trash my substantial license investment and know-how, which I'm not yet.
Conclusion: I think the Linux potential is much higher than you think. The Linux OS percentage is low - but large enough to get a lot more Fusion 360 customers - and it might actually steal some of the customers using competitors' CAD solutions today.