It's a real mystery why some fail, others don't. My '17 had less than 500 miles when mine went almost exactly a year ago. I had a 2012 bought new in '12, 58K +/- on it when I sold it after 5 years, and zero problem with the same system.
As far as damage, it's hard to say. When I changed out to Bilstein 5100's, I made it a point to check out my IWEs very closely, no damage to mine.
I've been buying 4X4 trucks since 1976, I've had quite a few, and the only problem I ever had was on a '97 F250HD, with auto locking hubs, hubs were junk on that truck, 3 times worth.
Hopefully, once you get this ironed out, you'll be good to go.;)

Yeah, it is just the luck of the draw. You also have to remember, most (not all) people only come to forums to complain, look for a resolution to a problem they are having, find out what the best thing is to replace whatever they want/need to replace or because they want to upgrade something. There are millions of these trucks on the road. It be nice to find out what the true percentage of failure rate is but, I don't think we will ever see a study done on that. Even 1% with millions of trucks out there will be a high number of people that will have an issue.

Dealer replaced check valve (FL3Z 3A788 A), so far no issues, but only about 100 miles since. I asked if the IWE hubs and actuators were inspected for damage and was told "no other issues were found". Hopefully, this was actually done. My guess would be that once the check valve tube was replaced and it passed the vacuum test, that was the end of it.

Also had TSB 18 - 2273 applied for hard shifting trans. Huge improvement with this so far.

Thanks again for the help and information from all who replied!

Ya, "no other issues were found" sounds a little evasive, but who knows. With my dealer, besides what is written, they would tell me. Olde gearheads stick together, ya know.
I had that TSB done as well when I had it in a few weeks ago. Did help, but when I have my tunes in, you really have to pay attention. My biggest issue was the surging between 1st-2nd. Yes with my tunes, it doesn't skip gears. Surged between 1st-3rd on stock tune.