It seems to me that the operative line:
> The President and the Attorney General, subject to the President’s supervision and control, shall provide authoritative interpretations of law for the executive branch.
conveys respect to the judiciary branch, and states that this only applies to situations where the executive branch is interpreting laws in isolation during their enforcement of them (which happens quite often).
However, following that line:
> No employee of the executive branch acting in their official capacity may advance an interpretation of the law as the position of the United States that contravenes the President or the Attorney General’s opinion on a matter of law, including but not limited to the issuance of regulations, guidance, and positions advanced in litigation, unless authorized to do so by the President or in writing by the Attorney General.
Feels weirder, because it implies that when executive branch employees find themselves between a rock and a hard place on when a law is interpreted differently between the President and Judicial branches they must follow the Presidential interpretation; or they'll presumably be fired.
The way I see it: This isn't a broad departure from the behavior of the system two weeks ago. The office of the President, especially under Trump, has regularly taken the action of replacing employees who are unaligned with the President's agenda. When the rubber hits the road and we get to a material matter that the President and the Judicial branch disagree on, what it might come down to is: the Judicial branch can bring a suit against the employees to follow their interpretation, but the President could fire them if they do, and the President could pardon them if they instead follow the Presidential way. That's, essentially, the same situation the American system has been in for hundreds of years; the only difference right now is that we have a President who might actually do that.
Which draws back to something I've said a few times: Presidents from both parties, over the past 50 years, but especially Bush and Obama, have been relentless in interpreting the law in a direction which centralizes power into the Executive. The "normalcy" of the office until Trump was never enforced through legality; it was only decorum. It was only a matter of time before someone rejected this decorum, born out of congressional deadlock and the dire state of many Americans' wellbeing, to make the government and executive branch actually do something about it.
This isn't the first time America has had to face this question; not even close. Trump isn't exposing new weaknesses in our system; the weaknesses have always been there. Worcester v. Georgia (1832) is a great example. It ended with the President saying F.U. to the Supreme Court, refusing to enforce one of their interpretations, and, well, the Trail of Tears happened.
"Weakness", however, is an interesting term to deploy for this; it implies that the default state of the American system is that you need supermajority alignment for the government to accomplish anything, and if actors in the system find a legal way around that requirement, its a "weakness". Phrased more simply: Strength is inaction, Weakness is action. Of course, many Americans would disagree with any assertion that this is desirable, especially in the unstable geopolitical and economic situation we're in. Trump was elected, by majority electoral and popular vote, to take action; most Americans would not call the cracks he is cleaving open to accomplish his agenda a "weakness" of the system.