I know on gas trucks it's included. If you look at fleet trucks there is a $50 credit for no oil change. It's not technically "free" it's just built into the cost of the vehicle. Look at your sticker under the "Owner Benefits" section, "First maintenance visit"
I didn't use mine because I bought an S10 Xtreme back in 2000 from the same dealer and got the first oil change free and when I changed it myself the next time I found they used the 4 cylinder oil filter instead of the 6 cylinder oil filter. I'd rather do it myself and KNOW what I've put on/in it. I also changed my oil the first time at 1028 miles.
My first service was free, They even filled my Def fluid and washed my truck by hand. I have just over 20k and have had 5 oil changes done and 1 fuel filter. The other 4 service's at my dealer was under $100. Give them a call it wont hurt to ask...