Yes, if you delete your photos from iCloud Photo Library, they’re deleted everywhere

Apple must not have explained iCloud Photo Library well to people, or folks just can’t conceptualize how it works. Our most frequently asked question in recent months, and one we’ve answered in various articles before, is usually posed like this:...
http://www.macworld.com/article/3136269/software/yes-if-you-delete-your-photos-from-icloud-photo-library-theyre-deleted-everywhere.html