I'm wondering how soon someone will push some code into production without writing unit tests because they can't be bothered to write unit tests.

People will write bad code regardless of language features. Ignore those people and worry about how people writing good code will use your new feature. If it saves them time, makes their life happier, or lets them write safer code, then it's a win. Similarly, if a feature helps bad programmers avoid today's bad-pattern-du-jour but prevents good programmers from writing good code, you should think twice before adding it. In summary: ignore bad programmers, they can't be saved by language features.