After restoring my iPhone from an iCloud backup, all my photos are greyed out. How can I get them back?
Turns out I solved the issue by just wiping my phone and restoring it from that same Sept 27 iCloud backup again. It had the photos in the backup after all. As to why it didn't download them to my phone when I restored from that backup a month ago, I'll probably never know.

Before I actually wiped/restored, I wanted to make sure that the backup actually had the photos in it. Of course Apple doesn't let you see the data in your backups, so I had to download a 3rd party backup viewer on my mac to look at the pictures in the backup file. Once I saw the photos were really there in iCloud, I decided to just restore from that backup and see what happens. It ended up working. Weird.