I believe DL strongly prefers the 10, and they are very well aware of the delay. I don't foresee them following UA on this

DL might not have a choice in the matter...I would not be surprised if Boeing winds up cancelling the 10 altogether. It's not just commercial aviation that might be impacted by this as there is an insane amount of political pressure on Boeing now and that can bleed into defense contracts. Cancelling the 10 as a symbolic gesture to "prioritize the safety" of the existing a/c they are building might be a wise move to keep politicians and those who sway defense contracts happy. If Boeing can force as many customers into the 9 as possible, that is a very big win for them and efficiency and getting their output back on track. If they lose a few contracts, its a small price to pay for not losing additional business and the ability to get back on track.

We've had this discussion already. I couldn't disagree more. Boeing cancelling the 10 would be admitting defeat and would show a fundamental lack of confidence in the Max as a whole. That's not how you repair a brand. I'm confident Boeing will get the 10 certified. I'm also confident you won't agree, so I'll leave it at that and agree to disagree

The same issue preventing the MAX-10 certification is holding up the MAX-7 as well (which have already had multiple units fully manufactured and waiting to be delivered to WN) so they definitely won’t cancel it. It seems like a joke/safety theatre as the same de-ice safety sensor that’s holding up certification isn’t equipped on the MAX -8 or -9 as those were given a waiver by the FAA to operate without it. What makes the -7 or -10 different from a safety standpoint that they can’t be given a waiver? If there’s no difference then why aren’t all MAX-8 and -9s grounded?

Because at this point its not just Boeing that is on the hook... its the FAA and their certification process. If they give exceptions/waivers/whatever and something happens then whatever is left of their credibility is also totally shot, and people there are covering their assess and careers and political connections.
The MAX should've never been given all of those exceptions and waivers in the first place and thats been made abundantly clear with political contributions etc getting into the FAA process... now they're trying to look like they do the right thing be going 'by the book'.

That ship has sailed. So holding up two sub types of the same aircraft, makes zero sense when you've already given a waiver to other sub types. Either the sensor is needed on all or it isn't.

It makes no logical sense.

BINGO! Dealing with a government entity, the above fully applies :D

I recall a conversation with my neighbor several years ago, who is a design engineer for the 737s. He was not surprised that the MAXs were given waivers, because WN had put a lot of pressure on Boeing and the federal government to get a waiver so that the MAXs could continue to be called a 737 so that WN's business model could remain intact. He believed the MAXs should not have been given a waiver, but he did not care, because like most at Boeing, he was (and still is) there just to collect a paycheck. The 7/8/9 are all similar enough that if one is granted a waiver, the other 2 variants could be granted the same waiver (assuming it is correct to grant the waiver in the first place). The fuselage of the 10 is long enough and the engine placement is different enough from the 9, and the 10 is so reliant on computer systems to counteract the physics working against that a/c flying, that the 10 should be treated as a different a/c altogether. I have not spoken with him since the blowout (he is not my favorite person and he takes care of his yard and house with the same lack of effort that he puts into his work at Boeing), but I am sure his position has not changed - he is just there to collect a paycheck and does not care. He absolutely will not speak up or be a whistleblower, because that would involve more effort than doing the bare minimum. He is exhibit A of the cultural problems at Boeing. Where I live and where I work, I have a lot of interaction with current and former Boeing employees, which is why I am so concerned about the MAXes and the 10 especially. Things at Boeing are often done counter to what most expect, often illogically and often based on pressures from outside forces. They always bow to those outside pressures because fighting them or doing what is right takes effort. DL would be very wise to take the opportunity to drop the 10 and I am sure EB talking about how he does not know when 10s will be delivered is way to let people know that Boeing will drop the 10 when the new CEO takes over.