Does using CloudKit in your iOS include encryption which will make export compliance a requirement ?
No, per Apple documentation, you would not need to submit Export Compliance documentation if you re using encryption built into the Apple OS itself, such as CloudKit.
Encryption algorithm in use: Your app uses encryption limited to that within the Apple operating system
Required documentation: No documentation required in App Store Connect. Submit a Self Classification Report to the U.S. Bureau of Industry and Security (BIS) directly.
So you should be good to submit without provifing the export compliance documentation. However, if you are implementing your own encryption / decryption to encrypt the data before Apple encrypts it in their iCloud storage (double-encryption), you would need to fill it out. Most likely you are simply passing unencrypted data to the iCloudKit APIs, so you should be fine.