<p>Treating the universes, in the crossover, as the real deal would open a massive can of worms. They only showed Earth-89 (supposed
Burtonverse) for a few seconds, and had the Joker be alive. Treating Earth-89 as the actual Burtonverse would cause problems. Have they retconned the death of
Jack Napier? Or is this a separate Joker, who've emerged in the years since? No doubt, it would probably cause a lot of bad edits, by editors who assume one of the two scenarios to be the case (without definitive proof).
</p><p>Then, of course, is the Darkseid issue. He is mentioned in the <i>
Justice League</i> movie. However,
Darkseid was also on <i>
Smallville</i>. <i>
Chaos</i> establishes that there is only one Darkseid (him), in the entire multiverse, who travels between different realities. By treating Earth-167 as the actual <i>Smallville</i> universe, we'd end up in a scenario where any mentions or appearances of Darkseid in the DCEU (and any other continuity, that this crossover have placed within this one multiverse), would have to be considered a mention or appearance by
Darkseid (Smallville).
</p>