Per the subject, I have an iPhone 6 Plus and iPad Mini 3 where I did the "Erase All Contents and Settings". I was presented with my device passcode and finally my iCloud account. The devices went through it process to erase everything and I received an email that "Find my iPhone" has been disabled for each device. I then went to iCloud.com --> Settings and then removed each device from there. Then for iTunes in my MacBook Pro, I went to iTunes --> Account Info --> Manage Devices but I cannot remove all the old devices. The "Remove" button is greyed out. Will this cause problem with the new owner of the devices?