I remember a GM commercial in 1994, (because I graduated high school in 1994) stating that beginning in the 1995 model year, ALL vehicles will be equipped with DRL's. So, I'd imagine the Suburban had them, starting in 1995.
That being said, the dash indicator is lit on my '00 Yukon Denali, but they've never worked. And my '98 Suburban has them working, but they dont transfer to my snow plow during daytime driving, yet I have the additional wiring to do just that!
Edit: maybe I'll check for that T62 RPO code also!