“authoritative interpretations of law for the executive branch”
That means that if Congress passes a law with an implicit/explicit interpretation the Executive Branch can simply ignore that.
And there are no existing EOs that say Congress needs to overturn it. It has been the rule since forever that Congress makes the laws. Executive Branch implements it accordingly.
Implicit Yes, Explicit no.
This is basically a tightening of the "major questions doctrine". The idea is that Congressional law must be explicit or leave it up to the executive.
If law isn't clear, this states the executive decides, and it isn't a matter of supposing what congress intended, or would have wanted but didn't define.