The ability to set up alerts on the top 1000 items in a report was depracated recently (https://marketing.adobe.com/resources/help/en_US/sc/user/deprecated_alerts.html)
Please reinstate! This was a key functionality of alerts for us. As a publishing company, its ESSENTIAL for us to be able to see how an individual content piece (on a daily basis) is performing - and to be notified in order to respond to increased (or underperforming) readership. Without this functionality - we have much less visibility into how our news is resonating with our audience.