People send their private photos to their private cloud backups with the reasonable expectation that those photos remain private and therefore not a privacy violation.
If it transpired Google or Apple had staff looking through people's cloud photo backups, yes this would be considered a violation because "cloud backup" is framed as a personal solution and not a hosting or processing solution.
If it transpired Google or Apple had staff looking through people's cloud photo backups, yes this would be considered a violation because "cloud backup" is framed as a personal solution and not a hosting or processing solution.