Interesting. Even before I read Ford's response, I smelled a skunk in GM camp. It sounded like they have proprietary systems they want to hook and sell customers into. And then I read the article Bikeman linked, and realized I wasn't too far off.
Sure, GM wants sales, but the greatest profit center is hooking subscribers after the initial sale. (As in, let's take away customer's options and watch them grovel toward our proprietary solution). I view it like some companies that sell a subscription for heated seats to operate...or other features we buy once and use today.
My perception is that GM's approach is akin to taking away our right-to-repair. (Guarantee us revenue after the sale.) It reminds me of the McDonalds/Taylor ice cream machine fiasco.