Can you revive Master Khoga? [duplicate]

You will have the opportunity to purchase the missing boss pictures from Symin at the Ancient Hateno Tech Lab. They will cost 500 rupees each and will only be available after you beat the game. Just look for the Elite Enemy Picture set when buying pictures.

There's no "New Game+" as of yet but your saves will have a star next to them once the game recognizes that you have beaten the game.

If you have the DLC and haven't beat the illusory realm blight Gannons yet in order to upgrade your hero powers you can take a picture of them for your compendium. That will give you a second chance to photograph those "Elite" enemies if you don't want to buy the pictures.