A CA is the big news? LOL. Makes you wonder what the other "preliminary" docs they signed earlier - since you don't get much more preliminary than a CA. Big companies active in M&A sign scores of them in a year - and unless there's some "exclusivity" provision (which I'm sure they would have flogged in the PR if there was one), it's nothing more than a precursor to due diligence.
If PRs and 8-Ks announcing signed CAs became the norm in the corporate world, PRNewswire and EDGAR would collapse under the weight.