Wil went off on a tangent about his Wesley Crusher headcanon during the Trek the Vote stream.In my head, Wesley Crusher is a Time Lord? like the Doctor. He left with the Traveler and managed to bend space and time to suit him. So in those nine years he was exploring as much of space and time as he could and arrived at Will and Deanna's wedding looking the way his family from the Enterprise would expect him to look. They would expect him to be in a Starfleet uniform, and they would expect him to have achieved that rank, so he put himself in a form that would make them more comfortable but then immediately drew back into a ball of light and whisked away through the universe.