No kidding. I am shocked this works.
Does Firefox have a similar weakness?
It doesn't work. The person who posted the comment you're responding to has absolutely no idea what he's talking about. He confabulated the entire explanation based on a single misunderstood block of code that contains the comment «Remove " - Chrome Web Store" suffix if present» in the (local, NodeJS-powered) scraper that the person who's publishing this data themselves used to fetch extension names.
I don't see any evidence of this happening in Firefox. Either it's more difficult or they just didn't bother, either way I'm happy.
Edit: Can't find much documentation on exactly how the anti-fingerprinting works, but this page implies that the browser blocks extension detection: https://support.mozilla.org/en-US/kb/trackers-and-scripts-fi...
No. Firefox always randomizes the extension ID used for URLs to web accessible resources on each restart [1]. Apparently, manifest v3 extensions on Chromium can now opt into similar behavior [2].
[1]: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web...
[2]: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web...