Is that Tim Duncan's podcast? He's retired, who cares what he thinks?
Seriously, I'm a Celtics fan and it's not a crazy prediction. The Cavs destroyed a good Raptors team that only won two less games than us. They are the defending champions and they have possibly the best player of all time.
Considering where the Celtics are in their development, I would think stretching the series to 6 games would have to be considered a massive "win" for the organization.