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With or soon after iPads inherit iPhone's 4K cameras. The "3" came a few months after that generation of iPad's inherited the prior generation of iPhone's 1080p cameras. I'm guessing, this Fall's iPads inherit the 4K cameras and an :apple:TV "now with 4K" rolls out with them or soon thereafter.

OR, if one tries to see a pattern in all launches, the time between models is about 2.5-4 years, so the "5" would hit in 2018-19.
 
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