The continuity of the post Rebirth/Metal/Doomsday Clock DC Universe wants to have it's cake and eat it too, combining parts of the post Crisis and New Fifty Two continuity in a slapdash manner.
It seems that DC wants to have the history of the pre Flashpoint DCU while simultaneously being able to continue a large amount of the plot threads of their post Flashpoint continuity such as Duke Thomas, The Court of Owls, and the aftermath of Darkseid War.
Many of the creative changes that sprung out of the New Fifty Two are inherently incompatible with the canon of the pre New Fifty Two DC Universe. For example, Duke Thomas' existence depends on Zero Year being canon, which negates Batman Year One.