The lack of slavery does not moot or vacate these rulings — on the Fugitive Slave Laws, including Dred Scott — as precedent law with regard to what may be done to citizens by Federal police dicta, and to whether the states can say “NOT CONSTITUTIONAL”. This is the way of judges who follow a morally neutral philosophy of stare decisis, who subsume and vacate long established common law principles, for the sake of stultifying chains of logic based off of vulgar distempered and faddish legislation.
Also Wikipedia is - as usual - wrong about the details of the Act.
You're correct, laws on the book can be used as prescedent, but the basis/ruling for the laws you cited is property rights.
That's why I would consider these laws as "moot."
Citizens are not property. That's why I doubt anyone would go into Federal Court and argue the Fugitive Slave Law or Dred Scott to support the governemnt's right to "grope" airline passengers.