Complete fantasy. It would have been an express constitutional amendment. The court cannot legislate. It cannot strike down a constitutional amendment.
To overturn the North’s slavery forever constitutional amendment, it would take 3/4s of the state’s ratifying it. There were 15 states that still had slavery at the time. Ergo it would have taken 45 states voting for a new amendment to overturn the Corwin Amendment. That’s 60 which is 10 more states than we have even today. Don’t even try to peddle some ridiculous fantasy about how a whole bunch of new states would have been created to pass that one amendment overturning the Corein Amendment.
There’s no way around it. The original 7 seceding states could have had slavery protected by express constitutional amendment had they been willing to accept that in exchange for staying in. They turned it down. Protection of slavery was obviously not the main concern of either side.
There was no constitutional amendment protecting slavery. Utter nonsense but typical of the Neo-Rebs.