To transfer ownership of a snap to under Canonical, we generally require the snap to:
Be well maintained
Has at least one revision in stable
Has an icon
All the metadata filled out (e.g. summary, description, version, license, etc.)
Have a valid bug report link
This is particularly important as they will be linked with Canonical’s name and failing to do so may create the impression of incomplete/experimental software which is not what we want to convey from our maintained snaps.