> I'm sure they didn't magically find a hidden paragraph in 2015 regulating marriage equality.
Obergefell is a good contrast to Roe. Everyone acknowledges that the "rights" protected by the Constitution includes the rights inherited from the English tradition. (Liberals believe it encompasses an evolving set of rights based on changing moral standards, but they agree it includes at least those recognized in England in 1789.)
Marriage was one of those ancient rights. Even the Magna Carta includes rights relating to marriage. The question therefore wasn't whether there was a right to marriage, but whether same-sex relationships fell within the scope of the concept of "marriage."
On that question, the science changed dramatically in the period leading up to 2015. Science proved in the late 1990s that same-sex conduct was not a choice to reject conformity, but was rooted in biology. And in the early 2000s there was the first research showing that same-sex couples were living in committed relationships, raising children, etc. You'll notice that Kennedy spends a lot of time talking about these facts in his opinion--because those facts are critical to showing that same-sex relationships can be called "marriage" as historically understood.
If anything, "the science" has worked against Roe. The first real-time fetal ultrasound was conducted in 1971, just a couple of years before Roe was decided. Since then, ultrasounds have become routine, and 3D ultrasound technology allows us to see that a 15-week fetus isn't a "bundle of cells" but has a human face: https://youtu.be/sBmXNOG4s4A