Nudge of an interesting question

Hi Cécile, this question (see link below) has been asked and received no answer. Can you shed some light on it?

https://kwiziq.learnfrenchwithalexa.com/questions/view/why-is-the-subjonctive-not-used-in-the-phrase-il-ne-pense-pas-qu-il-sera-la-a-temps-i-thought-penser