What is happening, and happened years ago, is that many people stopped using Facebook messaging and went back to email. It's easier to get messages via email on smartphones than to run Facebook's app.
There is another, more benign phenomenon, where a company's PR department writes an article about the company, sends it off to a reporter, and says "Hey, we think you might be interested in publishing this (plus, we already did all the writing for you)" and then the newspaper edits it and publishes it as a regular article.
They see it as a sort of win-win situation. Reporters get an article to publish without any work, and companies get free / cheap PR.
Please specify for those of us that don't use it. There's been several apps known as 'Messenger' over the years.
Yes. At least among my social circle, it's become the go-to messaging platform.