They have been labeled experimental the entire time and off by default. That specific TC39 proposal is also approaching a decade of feet dragging and has been exceptionally slow to make progress. In Typescript if you aren’t opting into using decorators through a library that forces you to use them, they’re entirely avoidable (and some would argue, decorators make code worse and this failure to launch is a good thing).

I think the Typescript creators themselves learned a lesson with decorators and enums which is why we haven’t seen other JS language proposals get added until they’re actually in the process of being adopted (e.g. matchers).