This assumes a lot about a pretty mundane app. It seems more like Google is letting Slide do its own thing within the company. It was only acquired half a year ago, I'd be shocked if this is a precursor to a feature baked into Android.
Google pricked the group messaging territory with a little incomplete flag. Anything else I'm missing?
They're not "doing nothing", they're letting a small team try to develop something, which seems a perfectly appropriate reaction. How often has Google jumped into a totally new category with any real conviction? They half-heartedly launched Buzz long after Twitter was a hit, they killed Wave, etc.