As you may know, Canonical has been working a lot lately at the Ubuntu Touch OTA-6 Update, which is currently under the feature freeze.
While the system has already received the scheduled features, the developers are working hard at squashing bugs. Not long ago, Canonical ha replaced the four-week release cycle for Ubuntu Touch with a six week one, to permit the developers fix issues.
While Canonical itself performs a lot of automated and manual tests, the phone vendors also run their own tests, to make sure everythig is OK.
The Ubuntu developers have handed the Ubuntu Touch OTA-6 Image to Bq and Meizu today, so if we are lucky enough, it may be released by the end of this week.