The average maga cultist can't find their own ass with both hands and a CIA sensor suite. Of course they won't find evidence of anything: they don't know what to look for or where to look for it, a side effect of living in their information silo.
And it doesn't matter.
Once they have the epiphany that he LIED to them about the epstein files; not a campaign promise, not even his usual moved goalposts, outright lie: they will do the same thing every person who realizes the lie does: they question their relationship. That's the point.
Not all of them will do it, but enough of them. They won't suddenly open their eyes and vote democrat: they probably just won't vote. Or if they do, they vote for musks america party. They collapse trumps support internally. Because trump made a grievance foundational to his bases ideology, and then refused to follow up because he knew it would hurt him. He did it to himself.
Now it doesn't matter what trump does to the epstein file: it's bad news for him all the way down.