Missing in the original chart/data: have ML/DL job postings decrease more or less than other comparable job categories (programming, business analyst, etc.)
He's wrong and using not the best data for such an assertion.
Data science jobs are not slowing down, though they're not really increasing either.
In comparison since 2016 software engineering jobs revolving around building up systems for data scientists have increased 6 fold, maybe even more since I last looked.