So how does that make a difference to my point? The title is literally false as multiple other languages have already done it, Haskell in fact has even rewritten the underpinnings at least once the feature has been there so long.
The fact that X exists doesn't mean the "era of X" has started yet, you have to have the exponential adoption curve. The "Internet Age" started several years after the Internet was created
And clearly, adding this feature to Java is going to be like putting a web browser in Windows 95
