Even worse, in that discussion, it appears that there's a backdoor built into Firefox so that WebExtension-based ad blockers can't block Google Analytics. Only old-style add-ons can block it.
"It's as if the order to block/redirect the network request was silently ignored by the webRequest API, and this causes webext-based blockers to incorrectly and misleadingly report to users what is really happening internally."[1]
This is a specific issue with that preference page. You can easily observe that the WebExtension version of uBlock does block Google Analytics, just not on the about:add-ons page.
There are probably security reasons why add-ons can't modify about:add-ons. Imagine an add-on that could hide itself by modifying that page.
"It's as if the order to block/redirect the network request was silently ignored by the webRequest API, and this causes webext-based blockers to incorrectly and misleadingly report to users what is really happening internally."[1]
[1] https://github.com/mozilla/addons-frontend/issues/2785