How can Roe v. Wade stand if it was decided based on a constitution we no longer have in effect?
That is ultimately the question; what status do these rulings, alongside rulings made under the First and Second Constitutions have. All were modeled on the US Constitution.
This is in part answered by Article VIII of the Second Constitution which confirmed;
"All Legislation and Judicial Rulings not inconsistent with this Constitution passed prior to the Adoption of this Constitution shall remain in full force, unless superceded by subsequent legislation or Judicial Rulings."
This language was retained in Article VIII of the Third Constitution
'Prior' would include rulings determined under the US Constitution as in terms of Atlasia, we are considered a successor to the USA. Indeed, the legislative process refers to many US laws (Civil Rights Act etc) as being 'in force' as well as to laws created to replace or supplant US laws that were previously in force. Even Court judgements refer to US law and US legal precedent.
I have always considered therefore, and indeed it makes sense from a game viewpoint that all existing US law and legal decision was 'carried over' to Atlasia and this would include
Roe vs Wade