If the iPad has iCloud storage, will the photos on the iPad be stored and retrievable after a restore of the iPad?

If you are backing up to iCloud regularly (automatically or manually), or using the iCloud Photo Library option on the iPad, the photos can be retrieved yes. Otherwise, just having iCloud turned on, does not in any way shape or form store photos in iCloud.

If you are backing up to iCloud, then the photos are included in the backup if set to do so in Settings and can be retrieved by restoring said backup onto another iOS device.

If using iCloud Photo Library, you can log in with your Apple ID at https://icloud.com and view the photos in the Photos web App there.

They will be part of your iPad backup stored on the cloud. They will then be able to be included in a backup restored to a new iPad or accessed by other iOS devices you have with the same Apple ID in the cloud. iCloud in itself is NOT a storage/archive medium.

What is it you are hoping to do?

Photos will be restored only if you include them in the backup. Your backup contains whatever you select in the iCloud backup. I used to backup photos/videos when there were only a couple of GBs. I stop backing up photos when I hit the free 5GB iCloud storage. My iPad will not recover photos from iCloud but I have them in the backup (to my computer).