While you might think you need a site to promote your event, looking at the information you must provide could reveal that a single page is sufficient.
For example if an event is for a limited time, such as a day-long session, you’ll likely need a single page.
However, a multi-day event would likely call for a microsite with such pages as:
Introduction, describing purpose of event, who should attend, etc. (as determined by the Goals and Audiences descriptions on your filled-out checklist).
Daily schedules, with a page showing the time, place, and a brief description of each session on the agenda of that day's events.
List of speakers with photos and brief bios.
News page with a list of stories about the event, speakers, etc.
If you need to provide a considerable amount of information, you'll need a microsite such as the Anti-Racism and Inclusive Excellence Task Force site.
If there is a limited amount of targeted information, you only need a single page, such as the Sustainability page on the core site, which provides the information users need in one place, with hyperlinks going to primary sources of content.