Yep, though they also soon after made a further investment in Niantic. It may sound bizarre at first, but there might be good reasons why they did that. For instance, Nintendo might've been less likely to team up with a wholly Google-owned Niantic. (purely speculation on my part)
I strongly suspect a direct Google/Nintendo tie was considered less favorable than some little ex-Google company that still uses Google servers working on a Nintendo game. The announcement timing was pretty close.
https://nianticlabs.com/blog/niantic-tpc-nintendo/