There are millions of ways you could phrase the response (Dropbox and Microsoft used completely different language), the chance that these five came up with the phrasing used independently seems fairly low. Especially as the statements weren't all given to a single reporter (who could have phrased the question in a particular way) but rather to a variety of different news sources.
It could still be completely innocent, they could all have cribbed off whoever did the first denial or they could have discussed it beforehand and co-ordinated messages without there having been any government involvement.
It is however something that needs explaining.