I have a 2014 that I bought two years ago with 60,000 miles on it. I changed all of my fluids over the next few months. When I changed my trans fluid at 68,000 miles I looked over the valve body. There was one bolt backed out a few threads, and another I was able to turn using only my fingertips. They were both holding the accumulator plate on, which is one of the weak links of the stock valve body. I tightened them back up, and at 72,000 miles, I removed it, and put on a Revmax valve body, deep pan, and trans cooler solenoid bypass. I also got a tuner for the truck in order to run higher line pressure. I'm currently at 88,000 miles, and haven't had any issues.
As far as the emissions cleaning, they are trying to pull one over on you. The first version of EGR systems required you to remove and clean them closer to 75k, maybe 100k miles. They changed up the systems and this isn't necessary anymore. It isn't on my 2014, and your 2018 should be the same components.