Jokes necessarily often leave behind details to work.
Here the whole joke is pointing out similarities we see are forced.
And besides, it's obvious the author was intentionally being "wrong", otherwise we'd be suggesting the author assumed the thought-experiment was monkeys who knew language, intentionally typing out great works. That's a pretty useless situation to make up, it doesn't suggest anything interesting.
The meta of the joke, as well as the philosophical idea that underpins it, is that the universe is based in probability and we are the result of those infinite dice rolls eventually making a human race that can think and be conscious and create Hamlet.