That’s inaccurate. VCV is GPLv3 licensed which is not allowed on iOS. Again there are old threads in this board which mention when this was changed. VCV would need to modify itself with a different license to make it compatible with Apple’s policies, since derivative works have to be GPLv3 too.
Plugins like VSTs are allowed on iOS. Eventide’s plugins are AUV3 and work in a music hosts like AUM, Drambo, and others.
Plugins in VCV are not the same as VSTs/AUv3, they are essentially extensions of the core product similar to modules in Audulus or Max. There wouldn’t be an issue running them on iOS. Many iOS music apps also have in-app plugins and downloads like Steinberg’s Cubasis DAW has its own in-app purchase downloads like compressors, etc