This was the other big nugget from the article:
(Hanlen, who also trains Joel Embiid, also considers another alternate history: "I begged the Sixers to draft Jayson because I knew that pairing Jayson and Joel up ... I really thought that they would be the biggest tandem in the NBA.")
Things worked out perfectly for us to get JT.
I may be wrong, but I think Hanlen & Tatum had some apprehensions about joining the Celtics because they saw Hayward, Morris, Brown & Smart as obstacles in Tatum getting consistent minutes, which makes sense.
Before the 2017 NBA draft, the 76ers had no established players other than Embiid (who Hanlen knew was going to be a star).