Elevated EGT's do nothing good for the engine. Sort of like an auto transmission, up to a point temps don't affect durability too much, but beyond that point wear goes up dramatically.
IMHO, 1350 df should be the target maximum EGT. Beyond that, ICP's are getting excessively high, exhaust valve temps will be cooking, valve guide wear and even some errosion of the piston crown may become evident.
Dodge doesn't need to warrant the engine beyond 100,000 miles, so they don't need to be concerned about accelerated wear as long it doesn't cause the engine to fail within 100,000 miles.
It's been a while since I looked at the Pyrometer on a big Cummins or Cat, but seems to me that 1350 df or so has been redline. Though the valve seats are supposed to be a different alloy to help with the problem, there is only so much they can do with metalurgy, oil squirters, etc. . to deal with the high EGT's produced by the new emissions equipment found on the 6. 7.
It's a real dilema. Do you pull off the DPF and do an EGR block voiding your warrantee and possibly running afoul of Uncle Sam, or do you go for reliability and fuel economy?