You have things a bit backwards. The try operator was not conceived until after sum types and traits were already stable parts of the language. The addition was

You have things a bit backwards. The try operator was not conceived until after sum types and traits were already stable parts of the language. The addition was simple, didn't really alter the language in a meaningful way and is almost purely syntactic sugar meant as a quality-of-life improvement for users. (ie. it hits pretty every single point in the article's definition of microfeatures)