>The article states otherwise
No it doesn't. You're ignoring the context.
You can't have too much iodine when it's obtained from iodized salt.
...because you can't handle that much salt.
From the article: 10x'ing the concentration of iodine in salt had no adverse effects. You'd have to eat salt by the pound daily to reach levels where iodine is harmful, but at that point, that'll be the least of your worries.