Last season, the Celtics were just one game away from the championship, and now, with Hansen gone from the Cavaliers, their strength has significantly declined, leaving no team in the East able to directly defeat them.
As for the West, the Pelicans were swept in the finals, showing a gap in strength compared to the Celtics; the Rockets' Paul always tends to falter at crucial moments; although the Kings have Hansen, the rest of the team are still rookies needing time to develop; the only team that could potentially threaten the Celtics is the Warriors, who are also facing uncertainties with their new season adjustments.
So, Durant is not overly confident; he's merely stating facts.
It makes sense for him to thank Hansen, because if Hansen hadn't left the Cavaliers, the Celtics would have only lasted another year before being dismantled like the old Heat Team.
"Well, good luck to you."
Hansen offered his blessings to Durant.