Given that Linux mode is a directly supported feature of ChromeOS, I think it gets a little bit murky. A consumer grade device with Debian Buster/10 I can just run Emacs on? True it's not the Ubuntu+Gnome running natively future we wanted in our desktop domination (though Dell and System76 and Framework will sell you one of those these days), but Chromebooks aren't this totally locked down bastardized single-app technicall Linux device with that feature. Chromebooks also now run Android apps too.
If 99% of people don't know what Linux is, and don't use Linux mode, should it really count? Most people just use what is essentially a browser that can also run Android apps.
If 99% of the people using it don't know what a Linux is, I think that means we've totally won because it means that Linux got easy enough for them to use!
Really though, I think it's for you to decide. It's not like there's a standards body with a rigorous criterion on if a given year is "Year of Linux Desktop", which is perhaps OPs point. Personally I think that 2013, when Dell first started selling the XPS 13 with Ubuntu was the Year of the Linux Desktop and I personally think that we've actually lost the plot in subsequent years.
Given that ChromeOS uses Linux under the hood? I'd argue yes it does count. Even if they don't access Linux mode/Linux VMs they are still using a Linux system.
fair enough, I do think it's arguable that users of ChromeOS would regularly do that, but I get your point.
Also, I had a System76 laptop for work once and absolutely loved it. I tried to buy it when I left, but they weren't happy about my reasons for leaving and refused to do so.
https://support.google.com/chromebook/answer/9145439?hl=en
Eg Instructions on how to run Firefox on ChromeOS with Linux mode
https://support.mozilla.org/en-US/kb/run-firefox-chromeos