In that topic what does “Reply as new topic in the right gutter (UI removed)”?
That topic is out of date. In versions of Discourse before 1.6 “reply as a new topic” was a link that appeared in the right gutter. The entire right gutter UI has since been replaced with the custom timeline.
In order to reply as a new topic now, you use the share icon. Presumably that UI is hidden for TL0.
Will it be updated with new information soon?
Other than that one line you found, I believe the rest is up to date!
You would need to ask @codinghorror nicely to update it, shouldn’t be too difficult to fix.
Done, thanks for reporting