The scoop is that QT LTS is becoming (or is) closed source. I don't know what that means for KDE, but I hope you're right.
And since my phone doesn't have image stabilization either, I sometimes have to 'take the shot' when I exhale lol.
KDE is likely going to follow with KDE6, like when QT went from 4 to 5, KDE followed, although to be honest i have not searched, just going from what happened last time, and Qt5 was already in part closed source, no? KDE from what i understand also has blobs so i do not think it would bother them too much either
and really should not bother you too much, you can still opensource your code, just peoples will need a propitiatory library to compile it, a lot of projects works like that by lack of better options, and once you know one, you have bases in them all, so nothing is lost.