An extremely poor description of Planck's results. It would be better to say that QM was born out of an interpolation formula. There was no "leap of faith" only a (much) better explanation.
Planck invented a forumla that interpolates between low and high frequency black-box radiation behavior. The results of the formula were so good, that Planck asked the question, what physical mechanism could describe his formula. The rest is History.
Otherwise the article seems a reasonable description of things.
I agree with Physicist about his misgivings concerning "Planck time". I understand that the Planck distance is probably the minimum distance a photon can travel such that the distance has any meaning. But this isn't the same -- at least to me -- as saying that time is quantized.
Here's another article on this topic, in Nature.