To celebrate the release of volume 3 of Tsubasa – WoRLD CHRoNiCLE –, there will be a special chapter of Tsubasa in the upcoming double issue 37 & 38 of Weekly Shonen Magazine, out on August 10.
In a similar fashion, a special chapter was published in Weekly Shonen Magazine to promote the release of volume 1. That special chapter would be later adapted into the PLAYBUTTON audio drama that comes with the limited edition of volume 3.
Source: Weekly Shonen Magazine.
Image credits: clampPROJECT.
Update: According to CLAMP-NET.COM, the special chapter will be entitled Tsubasa – WoRLD CHRoNiCLE – Kinugawa Onsen Hen, which means it will be based on a recent trip CLAMP did to Kinugawa Onsen. This contradicts what they said on their radio show when asked if the Tsubasa gang would be landing in a Kinugawa Onsen-like world and they replied that the trip was not for Tsubasa, but for a different work. Unless that question gave them an extra idea?
On another note, according to AnimeNewsNetwork, the magazine where Tsubasa – WoRLD CHRoNiCLE – ran in, Shonen Magazine SPECIAL, is ceasing publication in January 2017. This means that whenever Tsubasa – WoRLD CHRoNiCLE – returns, it will most likely run in a different magazine. Kodansha has another monthly shonen magazine, Monthly Shonen Magazine, where it could be serialized in.