The guy is being a bit loose with the terminology.
If I take the "cloud computing" to broadly mean "on-demand availability of computer system resources," that is not going away and is not losing popularity.
"Cloud" can also be run on-premise.
Even if we restrict ourselves to talking only about the "public clouds," the revenues of AWS, Azure, and Google Cloud are all still growing very fast. The growth rate may have slowed as the market matures, but it's still growing, not shrinking.
Yes, they are companies that leave or reduce their use of the public clouds, but on the net there is still more in-flow than out-flow for the public cloud business.