Multi-Output class_weight parameter removed?

I am interested in applying loss function weights to a multi-target model using the class_weight parameter in .fit but it appears that it cannot be used past version 2.1. In 2.1, it looks like you could input a dictionary with the classes and their corresponding loss weights. Does anyone know the reason this was removed or is it a bug? Are there any workarounds to apply this kind of weight?

A quite long story in: