I think you should watch the first 20 minutes of this talk: https://youtu.be/Dq2WQuWVrgQ
Java's early designers realised (or believed) that the features with most bang-for-the buck weren't linguistic, but were: GC, dynamic linking, and performance with observability. Linguistic features, overall, were a detractor from those, because people were hesitant to use them, and so they missed out on the big benefits. Java decided to provide these most important features wrapped in a language that was non-threatening at the time; James Gosling called it "a wolf in sheep's clothing." In other words, a familiar language was a very central part of the strategy. You say you believe it would have worked with a non-familiar one, well, we can never know, but if it hadn't, then much none of the other, more important features would have mattered.
> But the fact that Java and essentially all other successful languages have gradually been adapting essentially all of ML (sans modules), is evidence
As I said in another comment, it's not that all successful languages are adopting ML's features but some, and those ones do it because they influence one another and they knowingly borrow from ML because they like it. In other words, the designers of some influential languages like ML. Is it a coincidence? I don't know, but I'm hesitant to say that it's evidence that ML was "right." I, too, personally like ML, but I wouldn't claim its design leads to better outcomes than others. Some successful language clearly do not adopt ML's features -- e.g. all the untyped ones and Go.
BTW, Java's objects are a different take on modules. If you've seen 1ML, that's almost an OO language.