I think they’re just going to look at it as a contract between 2 people...and nothing more. No religious or moral application.
Exactly right. And therefore they will be merely clarifying a tax-and-benefits legal definition.
What really needs to happen is that this administratively acknowledged contractual agreement needs to be called something other than "marriage" for everybody. And the word "marriage" has to go back to where it came from: a joining acknowledged by a spiritual tradition between two people and God, based on love - and completely outside of government jurisdiction.