Files created by Facebook, depicting the trademarked Facebook logo, are copyrighted by Facebook. Files created by Feather, depicting the trademarked Facebook logo, are copyrighted by Feather. If the latter is freely licensed, with no restrictions on use, you may use that image in whatever manner you please. If you use it in a manner that generates brand confusion with Facebook's business, Facebook may, as a trademark enforcement action, order you to stop using the image in that way. They cannot make additional copyright claims.
It is likely they will anyway, under the assumption that no one but Facebook would create files from scratch for corporate logo images, when the company itself distributes gratis images of its logo to anyone who wants to put one on their website. But if they didn't make it, they can't impose prior restraint on what you do with it via licensing terms.
Facebook may impose copyright licensing terms on its own images that support its defense of its trademarks, but those terms have nothing to do with the image by Feather, or any other clean-room implementation of the Facebook logo.