Metroid Prime 4 is in rapid development for Nintendo Switch, and speculation is rampant about the role that Samus’s rival Bounty Hunter Sylux is to play in the game. Prime series producer Kensuke Tanabe previously confirmed rumors that Sylux was the pilot of the ship following Samus at the end of Metroid Prime 3: Corruption, and now, we can confirm another rumor about Sylux: he did in fact make an appearance at the end of Metroid Prime: Federation Force as well.
I recently discovered the ArtStation profile of Logan Foster, a contract environment and prop artist for the game. He says he designed the ending scene, and flat out confirmed that the character in that scene is Sylux. He also confirms that the scene is set on a Federation research station. It was one of the first things he designed for the game. You can see the ArtStation post for yourself below, but in case it is removed at Nintendo’s request, it has been archived over on Wikitroid.
Source: ArtStation