Something really profound must have happened to Wonder Woman when she ascended into the beyond with The Hands at Death Metal's end... besides her becoming immortal and all that. It seems Diana's drive that once compelled her to stand against adversity to both protect those who deserved saving and to salvage those already lost has been replaced with a dark, existential outlook on life that a new impending calamity now exacerbates. In fact, the strategy she now espouses is quite similar to what Batman felt was mankind's best course of action during the Death Metal event as The Batman Who Laughs continued to shape every world in his image.
In Death Metal, Batman was convinced that their only hope was to save those who The Batman Who Laughs hadn't yet killed or turned into one of his lackeys. Anything else would have been a fool's errand. To take that phrase one step further, Wonder Woman made herself into quite the fool when she not only ignored Batman's advice, but actively did the exact opposite when she murdered The Batman Who Laughs. In Future State: Immortal Wonder Woman #1, written by Michael Conrad and Becky Cloonan with art by Jen Bartel, Diana now believes that the Amazons must flee Themyscira and create a new world rather than protect their homeland from the so-called Undoing.
One of Diana's sisters blames this outlook on the years she spent immersed in human life, an opinion with which Diana later seems to agree. And yet, this couldn't be the case as she didn't feel this way when she actually fought alongside humans during Death Metal as a mortal goddess. It's only after descending from the beyond as an immortal deity that she reaches this conclusion.
Some could argue that because, earlier on in the issue, Wonder Woman thinks back to an intimate moment she shared with Batman that her sentimentality for humans is a main contributing factor towards her urge to flee, especially since she believes Bruce Wayne is dead. While that's undoubtedly the case, a counterpoint could be made that her mind subconsciously chooses to reminisce about Batman because she finds herself adopting the very same views he once adamantly supported in a similar situation. Also, if sentimentality is what truly drives her, wouldn't Diana want to stay and protect the home world of the people for whom she's ostensibly feeling sentimental?
Regardless, it's interesting to note that not only does Diana believe that the Amazons should find a new world, but she actively tries to tarnish the legacy and future of their home to help make her case. At one point, she reminds her sisters that Themyscira hasn't been the paradise their people hoped it would for a millennia. Diana even seems to imply soon afterwards that it never would be that way again, for, as she says, when the age of man ended, it didn't signal a rebirth for Themyscira as mankind had already infected the Earth to its very core. Based on this comment, Diana is essentially saying that Earth is too far gone for Themyscira to ever become a paradise, so trying to save such a place is a lost cause.
Ironically, Diana only decides to stay and fight when she sees a comet falling from the sky, signaling the beginning of the end. They're all going to die anyway, so why not go down fighting? Regardless, the concept of Wonder Woman turning into Batman actually manifests on a physical level beyond her just thinking like him. At one point, Diana takes the utility belt that once belonged to Bruce Wayne and straps it around her waste in honor of the man she thinks is dead. It's just a utility belt, but it's one step closer to becoming the Dark Knight.