A status column with six string values is not a state machine. The machine is the transition relation:

fn allowed(from: Status, to: Status) -> bool {
    match (from, to) {
        (Status::Received, Status::Validating) => true,
        (Status::Validating, Status::Submitted) => true,
        (Status::Submitted, Status::Pending) => true,
        (Status::Pending, Status::Confirmed) => true,
        // ... every state may fail ...
        _ => false,
    }
}

Its value is entirely in what it returns false for. The catch-all _ => false is the design, not a formality: every edge you did not write down is refused by construction, so adding a seventh status later fails closed rather than silently permitting a dozen new transitions.