All mainstream editors that agree to work on a standard AST for any given language could be nice. I'm not expecting that to happen at any time in future.

About grep and diff working on a textual representation of the AST, it would be like grepping on Javascript source code when the actual source code is Typescript or some other more distant language that compiles to Javascript (does anybody remember Coffescript?) We want to see only the source code we typed in.

By the way, add git diff to the list of tools that should work on the AST but show us the real source code.