Did Apple delete photos from my iPhone 11 due to not enough dpace in iCloud for backup?

After upgrading to iOS 18 I had about 6 GB of free space on my 64GB iPhone 11. I started getting messages and a red dot saying there was not enough room for my 50GB iCloud to back up my phone. I never got around to deleting or transferring photos from my phone, but now I have 18 GB of free space on my phone and there is no more mention of backing up. On iCloud, it says that the entire 50GB is full. How did I get extra space on my phone? Did it delete something