It won’t, the evidence was live ammo from seemingly the same source as the live ammo found on the set of rust, and this batch of ammo traces back to the armorer and her father. It would be great evidence AGAINST her, but she was convicted without it.

Against Baldwin however, this new evidence is completely pointless. No one was ever claiming that he supplied the ammo, brought it onto set, loaded it into the gun, or even failed to identify it before rehearsing the scene (because he didn’t even check). The prosecution’s narrative of events is that Baldwin pointed a real gun at a person, cocked the hammer, and pulled the trigger, which resulted in the death of one person and wounding of another. That he knew it was a real gun, blank rounds were on the set, and that blank rounds can, and have, injured and killed people.

Finding the source of the ammo does not prove that Baldwin did not point and fire the gun, so the evidence is not exculpatory in regard to the actual charges against him. The defense could theoretically used the evidence to impeach the testimony of another witness, but who they would impeach or how that would be relavent to Baldwin and his charges, I have no clue.

Edit: here’s a link to self defense attorney Andrew Branca discussing the dismissal, it’s 43 minutes but starts right away https://m.youtube.com/watch?v=EYNRR3wr3BY