Waymo doesn't gain anything. Google i.e. Alphabet Inc, does.

Especially these days. Every scrap of news that could pump the stock price is publicized aggressively.

And this makes the absence of such actions suspicious.

Not really: this past few years, listed companies tend to be _very_ pessimistic on their quarterly projection, and then reveal that either: it wasn't that bad, and nothing change, or that is was great, and their valuation shoots up. Weirdly the market doesn't react over those pessimistic projections, so it seems it's just a safe play for CEOs. They started doing that in Europe as well.