No. Just no.
Without jumping into too many details, the fact that the difference between mutable and immutable variables is a single character (var vs val) means developers are prone to typos and readability problems.
Overall this language seems to be a step backwards in terms of readability. I’m all in favor of better/newer language, but only if they improve readability. Adding “cool stuff” into the language just to seem hip doesn’t hold any value.