What's the reasoning behind giving special effect only to some class BP weapons?

Lately there are always only 2-3 classes that have some glow/fiery/mist/whatever effect on their weapons and other classes only have the bland model. The current one has the special effect for wizard, necro and tempest (seems like these calsses always have a special effect on their weapons) and nothing for the other 5 classes. The case was similar with the previous bp skin “ordeal of steel”.
Unfortunately I can’t insert images but everyone can check the bp weapons on youtube, here for example
https://www.youtube.com/@jaykhan619/videos

Maybe GhostSignals could ask around why some classes are missing special effects while others got them?

The instructions for how to do this have been linked to over 120 times…

I wish Blizzard would pin mine or make their own blue post with the instructions.