Bull. I sled pulled for 10 years and worked in a diesel performance shop tuning this things for a lot of those years. An intercooler does lower EGTs. I’ve seen them drop EGTs by as much as 200 degrees going from non intercooled to intercooled. Furthermore, that’s part of the reason the big guys on the pro circuit run ice boxes. Along with water methanol injection systems. Cooler, charged air not only makes more power but it lowers cylinder temps, assuming you leave the fuel pulse and injection timing alone