When did you buy your truck?
Windows XP was released in 2001, and they supported it until 2014. Computer hardware is generally obsolete in about six-eight years with the current pace of development. So, they supported the product for twice the average lifetime of any hardware that it was sold to operate.
So, does GMC support your truck for twice its average lifetime, free of charge?
They have better support than microsoft. They are hardware and the software is supported as long as the vehicle is functional.