"Visual Studio-ification": Any technology that requires Visual Studio to be productive. The classic example would be TypeScript, but you can clearly see nushell's overtures to VS in the linked article.

A de facto requirement on VS to make a webpage is bad enough, a de facto requirement on VS to write a shell script is even worse.

Hover/go-to-definition seems more like a nice-to-have than a requirement. Either way, neovim support can be found here: https://github.com/LhKipp/nvim-nu

It has nice error messages so you definitely don't need an IDE to edit scripts.

Do you mean VS Code or actual Visual Studio? As someone who has unfortunately used both.