It's probably ~10 years old at this point, so it would seem they've had long enough to see the writing on the wall and port it to a newer technology. OTOH I'm not sure that, even today, the stability or penetration of WebGL is comparable to where Flash was at its height (to say nothing of the available talent pool.)
I've taken a screenshot[1] so anyone who doesn't have Flash can take a look.
For the abstractions Flash supported (objects with behaviors, scenes, timelines), WebGL is way, way too low-level. WebGL is more the kind of thing someone would write Flash on top of.
<sigh>
I'd imagine businesses and organizations where software and tech isn't their primary investment would take some time to move away from Flash, especially if they have a business that depends on Flash still working. It's probably similar to the scenario where there's some vital app that requires computers to stay on Mac OS X Snow Leopard / Mojave / Windows 32-bit.
The only option is throw out working hardware just because we can no longer manage it...
Or another example, older VMware setups that may not be fully upgraded yet (again perhaps with older hardware preventing upgrades). All flash managed.