If there is advice (e.g. Buy/Sell when X happens) and there is statistical proof it's a good indicator, then large companies with multibillion portfolios would act on that evidence. At which time their behavior would "correct" for the indicator. At which point there is no value to the layman.
Some opportunities can't scale to multiple billions in size, which means they persist as available inefficiencies.
So broadly speaking, yes. But specifically, maybe.
Additionally, one of the reasons bonds and yields work they way they do (per my understanding) is that all buyers aren't free. Institutional buyers (e.g. banks) are required by regulation to consider ratings.
So they have to park their large amounts of money somewhere, and they have a limited number of legal choices.
Also, if your timeframe is long-term, information in print is relevant, since a stock frequently trades in a region for months or years. In fact, there is a whole school of investing, value investing, that looks for companies the market is undervaluing. Generally they do this by looking at information in print but seeing it with more wisdom than the short-termers. (Problem is, wisdom is difficult to get.) But for short-term trading, I think Bloomberg would invite you to subscribe to the terminal. "Before it's here it's on the terminal" I think they say.
So if that's reliably actionable, why aren't billion-dollar investors shorting market indices right now?