I believe the question seems a little ambiguous and hence adding another answer.
Metadata and Custom Metadata Types are 2 entirely different things and showcase different behaviours, during Sandbox Refreshes.
Metadata in Salesforce is structural and to some extent behavioural
information maintained by the platform for every artefact type created
on the org, such as Custom Object, Custom Field, Apex Class etc. For
e.g. When you define an object, the Label the API Name, Description
and other details are the metadata.
Whenever a Sandbox is refreshed from a Production instance, this
metadata gets copied over to the Sandbox and overwrites the existing
stated of the Sandbox irrespective of the type of the Sandbox being
refreshed. If you are referring to records or data stored within an
object, then, those are copied over only in case of Full Copy and
Partial Sandboxes using Sandbox Templates.
Custom Metadata Type
Custom Metadata Type on the other hand is a Custom Setting like
entity that permits defining custom types which facilitate moving them
across instances during deployment. The key advantage is metadata
here, is stored as records thus providing the flexibility to transfer
them across environments.
They are moved over when Sandboxes are refreshed irrespective of the