I considered that but when you file it you loose access to informed delivery while they verify your old and new addresses via snail mail. Takes a few weeks before you get the confirmation code to get back in.
In the future I’ll be sure not to make the same mistake again but according to international tracking the package is already en route so I don’t think they’d be of any help for this package.
I think first point of contact will be with my new letter carrier woman, see what she says, it’s very rural here and she knows everyone and everything so I feel like I’ll have the best chance getting any help from USPS by going through her. I might try to contact my old carrier too, after 8 years of multiple packages a week he knows me and knows we’ve moved and will definitely notice a package addressed to me.