I wonder if, in that world, Lisp would be the boring corporate language, and HN would dream of a world where object orientation (which is clearly superior) never had a chance to leap from academia to the mainstream, and hackers post their niche flavors of Java and Smalltalk here.

Well, that world would also have CLOS - maybe the AMOP would be treated with the same reverence as the GoF design patterns book... ;-)

this article discussing how closure creation is disguised OO (and vice versa) might interest you.

https://wiki.c2.com/?ClosuresAndObjectsAreEquivalent