The "can be arranged" is the tricky part. E.g. you might know from context that some states are impossible (where the probability distribution is zero), even though they combinatorially exist. That changes the entropy to you.

That is why information and entropy are different things. Entropy is what you know you do not know. That knowledge of the magnitude of the unknown is what is being quantified.

Also, the point where I think the article is wrong (or not concise enough) as it would include the unknown unknowns, which are not entropy IMO:

> I claim it’s the amount of information we don’t know about a situation