Totally unpredictable. Like I said, this is the first time that an anime movie is released by all major chains.
Unfortunately, it comes during this very very hard times. Less than 55% locations open, 50% capacity restrictions, 3 to 4 daily shows instead of 5 to 6, three major cities still shuttered. All that plus ever-rising COVID numbers, the debate over quality of the vaccine .... it's a distracted nation.
Even Wonder Woman 1984 failed to navigate these troubled waters.
So I wouldn't put any burden on Demon Slayer.
Note:
Latest anime success was One PIece: Stampede (410k admission)
Also there's Stand By Me Doraemon's 1 million admission from way way back.