I don't know that her proclamation here is what exonerates him, being that she's fibbed before, she's damaged goods in terms of witness credibility.
I think you overestimate her credibility. She is literally claiming the things which she was convicted of are not true and that Epstein did nothing. We have numerous witnesses, including under oath in her own trial, to the contrary. I recall none that have "recanted" their statements against her or Epstein. She could never make those statements on the stand. She knows it, her lawyer knows it, Todd Blanche knows it. This doesn't mean that Trump *did* do something. It just means her statement is of zero value.
However, if there was even the slightest whiff of a possibility that Trump was engaging in "island stuff", certain media outlets would've locked onto it like a pit bull a few years ago and never let it go.
There are places for "absence of evidence" arguments, but frankly, this is not one of them. Once he became a politician, sure, I don't think he could have gotten away with any "island stuff". There certainly is plenty of evidence of his general sexual misbehavior in the 2000s with women in the 25-35 range, but (not surprisingly) nothing since he turned 65.
You seem to be overestimating how closely "Trump the celebrity" was monitored by the press and how much of his past behavior has been well reported. Reporters work on what they can find and the conclusions they can defend based on the evidence they have collected (including evidence that is not published). Think of all of those "Me Too" celebrity accusations that often went back decades, but were not reported, only to be revealed by public accusations.
There is reporting about Trump's misconduct (including felonious) with teens. The most well known has to do with the dressing room of the Miss Teen USA pageant. There is also reporting of Epstein throwing "model parties" for a couple of his friends and a couple dozen models (as I recall one former model attended such a party where other than teen models the only two guests present were Epstein and Trump and she got creeped out and avoid contact with the men), and the case of "Katie Johnson" who filed and then withdrew a federal lawsuit against Trump and Epstein in 2016 for assaulting her at Epstein's NYC home when she was a teen.
There is also Trump's (and Epstein's (and Maxwell's)) associations with John Casablancas and Jean-Luc Brunel, (FYI, you may not want to search them at work, but you should look into them) both of whom owned modeling agencies and had serious allegations regarding teen models. (Trump himself also created a modeling agency.)
I'm going to end with one more major thought. Epstein himself is spoken of having "up to 1000" victims in the press and they don't seem to have any qualms about using such a large number, but we have only a handful of fully open public testimonies given by the victims regarding their experiences. We also have some anonymous testimonies with details and a bunch of very partial statements. That is what the press has been able to report on a very large case. If Trump was involved it certainly wouldn't be at the level as Epstein and there would be even stronger incentives to stay hidden. Does this mean Trump was involved, no, but it makes it clear that the non-existence of reporting about direct ties between Trump and Epstein's crimes is not a demonstration that there are no connections.
This is definitely a case of "absence of evidence is not evidence of absence" and no conclusions can be drawn.
With regards to political figures, in more cases than not, deciding whether or not an allegation has merit isn't determined by who does or doesn't directly accuse them, but rather whether or not certain media outlets obsessively talk about it as if it's irrefutable fact.
It really isn't.