Apparently this has broad sweeping implications. I foresee a host of other legal challenges coming from this decision.
Remember, they cannot challenge a Supreme Court ruling, there is no higher "court" to appeal or challenge. Of course what will be entertaining is more talk from the Congressional and Executive side of the balance, stating that the Judicial side of the deal is not consequential and should be ignored. Well, they better go take the Civics class the dumb asses skipped before getting elected 50 years ago!
What is going to happen, is better. Related to the EPA and things is like when they want to change rules on the cars, like increasing gas mileage standards, changing the parameters for air pollution testing, making arborator like decisions such as we cannot make ICE vehicles after certain dates and bullshit like that. Congress will need to vote, be accountable and make damn laws now.
In our industry they keep changing the rules so that people cannot finalize licenses for new projects. So after they keep closing coal plants, we are now forced to purchase batteries, because alternatives like new hydro projects are all gummed up with their ever changing regulations after each administration.