As you may know, the Ubuntu Touch OTA-5 Update has been released in mid-July and not th developers are making plans for OTA-6.
For now, the Ubuntu developers have replace GGC 4 with GCC 5 on the Ubuntu 15.10 development branch, meaning that the developers have to recompile the apps with GGC 5 and to verify if the changes made meed the GCC 5 requirements.
According to Łukasz Zemczak, Canonical is still evaluating the possibility to release a hotfix release to include critical fixes before the OTA-6 update becomes available and next week they will decide whether to do this or not.
As you may know, Ubuntu Touch is a rather young mobile platform and Canonical releases a big update monthly. For now, there are three Ubuntu Phones: Bq Aquaris E5 HD, Bq Aquaris E4.5, Meizu MX4, but the system is also officially supported on the LG Nexus 4 device.