Typically any microservice that has a customer-facing endpoint should be added as a component in StatusIQ. As rightly said you should not expose the infrastructure components. As a best practice, add the endpoints as a URL monitor or a rest API monitor and have that as the component in the Status page.
For example, status.site24x7.com has many components. All components are URL monitors which are microservices of site24x7 (Apminsight's agent communication endpoint, rest API module's endpoint to name a few). If these are not reachable, that service is not reachable or may have intermittent issues.
On the other hand, if you want to group all the microservices into a single component, they have to be created manually. But once it is created you can automate creating and updating incidents through REST API or send an email to the component to update the status automatically.