Why do I need a GitHub account?
HACS uses the GitHub API to gather information about all available and downloaded repositories. Unauthenticated requests on this API are rate limited to 60 requests every hour. Because this is not enough, HACS needs to make authenticated requests. The rate limit for authenticated requests is much higher.
For authentication, an OAuth token with no scopes is used. It grants read-only access to public information (including user profile info, repository info, and gists).
You can read more about OAuth scopes here.
For more information about what and how often HACS updates or refreshes, take a look at Data sources.