"Winter" in AI (or cryptocurrency, or any at all) ecosystems denote a period of low activity, and a focus on fundamentals instead of driven by hype.

What we're seeing now is something more like the peak of summer. If it ends up being a bubble, and it burtst, some months after that will be "AI Winter" as investors won't want to continue chucking money at problems anymore, and it'll go back to "in the background research" again, as it was before.