The change was accepted several days ago but I don't see the changed text on the site. I don't mind because I know what I need to know but I wouldn't have bothered making my change if I didn't think it was something others could use as well. So now I'm wondering--how often does the documentation get rebuilt? Is this something I have to ask for?
Say that you install the latest version of Racket regularly (Racket 8.15). Then, in the development version, we added a function add2 to the language, with the aim to release it as a part of Racket 8.16. Wouldn't it be confusing to see the documentation for add2 on the documentation page when Racket 8.16 is not even released yet?
That's why documentation is frozen for "main distribution" packages (packages that are installed along with Racket installation, like rackunit, htdp, and the Racket language itself), and will only be updated when a new version is released.
For non-"main distribution" packages (user packages), they can be updated almost immediately after a change is published, and the documentation is usually built/updated daily.