The wiki is outdated since it states that there is no official version.
I believe you may be quoting the last paragraph found on the Installing Twine page of the Twine 1.x component of the Twine Wiki.
Based on the information in the Download Twine 2 to your own computer section of the Getting Started with Twine 2 page you simply need to download the relevant ZIP archive file from the main-site, then extract the contents of the ZIP file onto your hard-drive and then run the executable file.
Currently the Twine Wiki contains the guides for two different unrelated applications for creating Twine Story HTML files (Twine 1.x and Twine 2.x), and this unfortunately can lead to some confusion. Generally all pages related to Twine 2.x will contain twine2: in the file-name section of their URLs, the same way that all Harlowe related pages will contain harlowe: in their URLs.
NOTE: I currently don't have access to a Virtual Machine running Ubuntu 16.04 so I am unable to test the above installation instructions to determine if they actually work.