You are correct the information is provided by:
Property management company rep
Real estate agent
Lease management company rep
Instead of the property owners.
Since they work with multiple rentals they see the trends. To churn leases may provide additional revenue for the property manage to and lease management companies, but that shouldn’t devalue the trends they discuss.
Btw-I started including the “easy out with 30 day notice” when I realized how long & difficult a forced eviction can be. If someone violates terms of lease, I can give 30 day move out notice and not have to wait full 90 days of no payment for eviction (Covid19 muddied that up for now).