I don't think a 2020 release is unreasonable, but it depends on how much they plan to add to the game and how much they want to change up. I do wonder if maybe we'll have to wait a full development cycle, considering not too long ago Nintendo listed that it was hiring for the BotW sequel. It make me wonder how far along they even are. So optimistically, Holiday 2020. It could take longer before it releases. However, I do think at the very least we'll see more of the game shown at next year's E3.