It might depend on how the Javascript is being blocked. I use uBlock Origin advanced mode to selectively block Javascript (I imagine uMatrix is similar), and always have to whitelist discourse's CDN.
The difference is probably that selective blockers like uBlock/uMatrix don't show <noscript> elements, while globaly disabling Javascript does, and discourse might be relying on the noscript element (on mobile right now, so I can't check to be sure).
Re:Security advisory for crates.io
by steveklabnik on Tuesday September 19, 2017 @05:55PM
(#15289165)
Possibly, yeah; I went to about:config to disable it and triple check before I made my comment. Maybe it interacts differently with various plugins.
(With Javascript disabled, that page still renders, so I'm not sure why it doesn't show for you.)