I love the idea of a single source of truth. However, how does your approach handle browsers / plugins that modify the dom? For example, I can imagine Google Translate altering the textContent and some resulting downstream effects on business logic.

If the view needs to react to the updated DOM you could use a custom element and the attribute changed callback. If you don't need to react to if the updated text content would just be there the next time the view needs to read it.