Java is like Go with generics, exceptions, inheritance (which the author of Java thinks was a mistake), and a separate runtime (JVM).
Those four things alone are pretty big differences, and then there are more intangible yet important differences like stdlib and culture, and implicit interfaces. They are definitely in the same family, but not as closely related as you imply - they are not indistinguishable. I'd say the similarities are more in unimportant stuff like syntax, some of the differences are important.
I think one of the biggest differences is that Go has only value types and references thereto (including the builtin data structures, which are basically just fat pointers). Even if Java gets value types, there will be a huge and useless value/class dichotomy as in C#. But there are dozens of other misfeatures in Java, such as protected/final/first-class-constructors/explicit-interfaces/etc. And this is just the language--the tooling is even worse (and no, a huge, fragmented ecosystem of kitchen-sink tools is not "better" than a few, simple, purpose-made tools).
All that said, I have a lot of criticism for Go as well, especially as a language. I just can't see Java being on par with Go, even with generics. Of course Go has more than a decade of hindsight that Java didn't have (or at least Java was in too deep by then to make the requisite changes).
Basically applies to most mature widely used languages that have evolved by adding features. In many software projects, the bias is on the side of adding too many features and not accounting for the costs, to the point where someone feels a bit of pain and complains. In Go, the bias is in not having enough, to the point where someone feels a bit of pain and complains.
I'd bet that more language designers are going to opt for the 2nd strategy as we go forward in the 21st century.
The dynamically linked runtime and the JIT are indeed important differences (although not all JVMs share HotSpot's design; some JVMs compile Java AOT and statically link the runtime) -- but they are not
linguistic differences, and so nothing that the commenter I responded to could see in the code.
In any event, even regardless of how big you think the linguistic differences are, Java and Go are far too similar to like one and so strongly despise the other (although you could certainly prefer one over the other). We're not talking Go vs. Haskell, or Python vs. C here.
Those four things alone are pretty big differences, and then there are more intangible yet important differences like stdlib and culture, and implicit interfaces. They are definitely in the same family, but not as closely related as you imply - they are not indistinguishable. I'd say the similarities are more in unimportant stuff like syntax, some of the differences are important.