The core is LGPLv3, meaning that you can bundle precompiled versions and dynamically link against them at run-time provided that you provide means for your end-users to switch to their own version of the libraries.
Oh? When did they add that? Sneaky. I'm not current with what's happening with Qt >=5.
With all the threats and restrictions and enterprise pricing for commercial licenses, it looks like Qt is heading towards Delphi levels of irrellevance.