Learners don't receive a notification when moved from waitlist to active. How do you handle this?

Summary:

What's the workaround to let learners know they have been moved from waitlist to active?

Content (required):

We have found out that learners do not get notified when they are moved from waitlist to active learner. This is likely to results in learners missing events where they have been waitlisted but have actually got a space. Is there any workaround?

Version (include the version you are using, if applicable):

21C

Code Snippet (add any code snippets that support your topic, if applicable):