Right now, Quay has support for parsing labels, i.e. for determining the expiration of images: https://docs.projectquay.io/use_quay.html#tag-expiration

This functionality should be expanded to support metadata passed via annotations so that the functionality can support additional OCI types which do not use image labels.

A use case that this would support is to enable a way for Cosign to annotate the artifacts uploaded such that they expire alongside the images which they are attesting to.