This is why I hope someone can track down the Longwood alumni association’s podcast about Amy.
They interviewed Erin Sheridan, who was the FBI lead for Amy’s case (at least as of 2018, when the interview was done.)
She basically said that Amy was her first case as a new FBI agent, and when she was in position to revisit it in 2018, she had the poster updated and reposted to their site.
However, she also said that none of the reported sightings had ever been confirmed (ie, they had good reason to believe they were true). The case remains open because they don’t know what happened to her; I don’t recall her speculating one way or the other (foul play vs accident, which is fair enough.)
My memory has faded, but I think I posted some salient points she made in this thread right after listening to it. (On mobile atm so can’t easily link, but will later if no-one else digs it up.)