Current analytics intelligent alerts are much better than legacy alerts. These are some thoughts to enhanced Intelligent Alerts in 2019.
1. Ability to exclude/filter alerts on weekends vs weekdays. (Much awaited request since a long time) @ursboller has great workaround ideas here https://forums.adobe.com/thread/2598789.
2. Ability to add custom text alerts on certain future dates. Campaign start/end Dates.
3. Ability to add an alert on evar/prop value anomaly. eg. "standard" login evar value anomaly vs login event anomaly.
4. Ability to add an alert when a report is ready to pull in another system.
Please add more thought in comments.