With Cubed once being one of the majorly supported shaders for a very large time period, a lot of creators of avatars and worlds used it.
with it no longer being supported in the new VRC update, it would be useful for Cubed and other decrepit shaders to be replaced with a standard or another fitting toon shader if possible.
This is especially important because certain versions of cubed are currently so broken in the beta that they flicker rapidly, in world and on avatars. something that comes to mind immediately is the risk of causing epileptic attacks if someone is sensitive to the flickering. It can also appear in worlds, not just avatars, which given how long it takes to update content for some people, there is a moderate window of time where things will likely remain broken like this.
simply suggesting people to update their avatars and worlds is not enough as people have their own lives, and some of the shaders in question have been in use for over a year I can safely say. that means there is years of content to fix.