For extra links etc. this is being extensively discussed on Reddit at the moment [0]. As another comment pointed out, so far it seems reversible by setting browser.urlbar.update1 to false in about:config (requires browser restart) but it is apparently unlikely this will persist as an option.
2 comments
[ 2.8 ms ] story [ 17.4 ms ] thread@Mozilla: Can you at least not remove about:config entries to disable it, in the later releases, please.
[0]: https://old.reddit.com/r/firefox/comments/fwhlva/address_bar...