We see here yet again a return to the rule of law. In this case, we see that 'major decisions' are not to be made by executive fiat or by the Administrative State itself. The authority to make such decisions rests with the representatives of the people who are directly elected by them.
As noted by SCOTUSblog, this decision will reverberate throughout the out of control federal agencies.
There will be an abundance of legislation and litigation that will result from all of this.