I don't see that anywhere. Where did they say that? One thing I don't like about Lyle's reporting style is he uses too many phrases like "suggests" and "points to" and in this case "indicating". GM never indicated they are going to provide a 10 year / 150,000 mile warranty on the battery pack. Here's the exact quote:
What they are building a car for, and what they plan to back it up with are two different things. Many auto makers build cars to last 15 years and 200,000 miles, but they only back it up with a 3 year, 36,000 mile warranty.