You're absolutely right that there won't be any new testimony or evidence. At this point, however, there is no trial ruling to vacate. This case was resolved in district court with a pre-trial motion to dismiss. When appealing such motions, the appeals court doesn't look for judicial error; they consider the case
de novo — as if it were being heard for the first time. They're a set of fresh eyes looking at exactly the same pleadings and evidence as Judge Schofield did; Abdin isn't allowed to submit any more. In my article I explain the standard the Second Circuit uses for
ruling on copyright infringement; it's stricter than most other circuits and very different from the standard applied by the entertainment industry-heavy Ninth Circuit, like you saw in the Axanar suit.
The YouTube conspiracists' GoFundMe is basically taking advantage of Abdin's gullibility and complicity, and soaking Trek fans so enraged over DSC that they've lost their capacity for rational thought.