If instance is started with SSL enabled (e.g. Atlas) and if db.copyDatabase() is executed - the mongod will attempt to establish outbound connection with SSL. Effectively that makes it impossible for users to use copyDatabase() for data migration into an Atlas cluster as the target mongod, if started without SSL, will process SSL handshake and if it uses SSL, the certificate validation is likely to fail.
Perhaps we could make SSL use for the outbound connection to be optional? (for copyDatabase() only)