As someone who primarily makes a living from programming JavaScript, I don't think this is a good idea. Java may be a bit syntactically bloated, but it's a much better engineered language than JavaScript. The parts "fit" together in a more methodical way. And while a learner may be able to get started with JavaScript quicker, as they move into larger projects they'll find the quirky JS implicit type coercion rules to create hidden and hard-to-debug errors.

And with Java's emphasis on interface vs implementation, it's an ideal language for learning data structures and algorithms. I'd say if you struggle with Java's syntax in your first year of CS, you might have a hard time making it as a professional programmer or academic computer scientist.

If they really wanted to move from static->dynamic, I'd agree that Python would be a much wiser choice, even though it too has its idiosyncrasies. As jacquem points out, Python has the added advantage of a rich data science/machine learning ecosystem.

Also, if they really wanted to use the web ecosystem, maybe TypeScript would be another wiser possibility than JavaScript?

Edit: IMHO, perhaps the best didactic language is SML, but that appears to be a losing battle these days.