OK, it feels like this EO doesn't have the force of law and it's just Biden expressing an opinion. What am I missing?
All the requirements of Article V to pass an Amendment were met. There is nothing in the Constitution about deadlines or revoking ratifications.
It is not just Biden's opinion. After House members asked Biden to take action, he had legal scholars study the case.
Congress passed the Amendment
38 states have now ratified it.
OTOH
Congress initially placed a deadline, something like 7 years. That was extended to, I think, 1982. The most recent state to ratify was a few years ago, way past the deadlines.
Is having a deadline even Constitutional?
Also, 5 states have rescinded their ratifications.
Is rescinding a ratifications years later even possible?
Biden taking a role in this is ,highly unusual, but possibly no more unusual than Trump ruling by executive fiat.