$9K to replace an EB is a little disingenuous. You can find the crate motor from $7500-8400 depending on where you look, and the only reason to get one is to install it in something that didn’t come with it.
If you were just replacing the engine in a 15-17 Expedition, you can order a replacement engine from Ford (DL3Z-6006-A), which runs $5K. A new short block is $1,250.
If you were in there replacing it, and you wanted to upgrade to the Gen 2 EB from the 17 Raptor, it will set you back $5,250 or $1,500 for a short block.
Considering Ford charges $5K for a replacement 5.4 3V and $5300 for a Coyote 5.0, seems pretty much normal from where I sit.
Of all the things Ford could choose not to replace an EB motor under warranty for, lack of maintenance isn’t one that usually comes up. They’ve been building the EB since late 2010, if lack of maintenance were a concern, they wouldn’t let the oil life monitor go all the way up to 10K miles before telling the owner to change it. They wouldn’t have a leg to stand on to deny a warranty claim when it’s easy to track oil changes done at the dealer with a smartphone.
And the PCM decides what qualifies as extreme operation on its own and varies the oil change interval accordingly.
My normal interval is right at 9K, but when I towed my 9K pound trailer for 1K miles prior to my last oil change, it told me to change it at 7K miles. Pretty much right in line with what my last F-150 with the Coyote did.