This practice is called "Brand bidding" and is actually extremely common among competitors. Occasionally companies will mutually agree to not participate.
It's actually surprising why it's not perceived to be more hostile.
I don't know if this is still the case, but for a while the easiest way to get the best deal from Dominoes was to search Google for Pizza Hut with your adblocker turned off.
Ya this is kind of a non-story. They were probably bidding on 'Signal' prior to this current set of events anyways. And since Signal doesn't appear to be bidding on it's own name, Facebook is probably paying very little for that top spot.
Bidding on your name might be an even bigger waste of money than bidding on a competitor's name, especially for established brands. eBay's experience with this came up on a recent episode of Freakonomics - https://freakonomics.com/podcast/advertising-part-2/
Whenever I search for a brand by name and an ad for them pops up (in the rare case that I’m browsing without an ad blocker), I try to click on the non ad version right below it just to save them a bit of money.