I think that IDE functionality is fine for writing code, but shouldn’t be imposed for the UX of reading code, because code reading also happens a lot outside of IDEs, because it constrains the choice of editors, and because it creates fundamentally different “modes” of source code presentation. The visualizations will start to appear in comment threads like this one, and in other publications on the web, but copying them and pasting them into an editor will not work (will be invalid syntax). It creates unnecessary complications across the whole ecosystem. Language syntax should stand on its own, and shouldn’t need crutches like that to make it ergonomic to read.