Nothing has changed in the Constitution that would affect Buck v. Bell (or Plessy, for that matter; the Civil Rights Act is legislation, not an amendment, so if it were repealed, your argument would be moot).
Your statement was
The Court reverses itself for many reasons. Sometimes, it's because the Court got it wrong the first time. Sometimes, it realizes the error as a result of evolving knowledge. Are you saying we should perpetuate a bad decision to avoid "evolving?'
No, i'm saying that just because the supreme court is wrong doesn't mean that we shouldn't read the constitution in a more direct sense.
For example, how they misinterpreted the Commerce Clause to shove their stuff down our throats from the feds.