Tuukka Turunen, Qt Development Director, announced that the license of some Qt modules has changed from LGPLv3/Commercial to GPLv3/Commercial. By the time Qt 5.14 is released, the license will change for the Qt Wayland Compositor, Qt Application Manager and Qt PDF modules. This means that to circumvent the GPL restrictions you will need to purchase a commercial license.
Since January 2016, most additional modules for Qt have been released under the GPLv3/Commercial license, and it is unknown whether this will continue.
Discussion on the mailing list: https://lists.qt-project.org/pipermail/development/2019-October/037666.html
Source: linux.org.ru