Give the option to:

1. List only issues that have Milestones, which I imagine would be just an option:

{
    "onlyMilestones": true
}

2. Create release notes based on milestones rather then on dates. only applicable to issues
   To achieve it we need to create a matching system between the tag name and the milestone naming convention.

{
    "dataSource": "milestones",
    "milestoneMatch": "Release {{tag_name}}"
}

3. Use the description of the milestone in the release body.
4. Consider to filter only closed milestones (?)