> Well tweets aren't legally binding

There's nothing in general about a tweet that makes it any more or less legally binding than any other public communication, and they certainly can be used in legally binding ways. But sure, a simple assertion to the public from the CEO of a privately held company about what a separate contract says is not legally binding - whether through tweet, blog, press release, news interview, or any other method.

companies like saying things that makes it look like they aren't doing anything bad but then they decide to do exactly what they said they wouldnt

e.g. google project maven, microsoft hololens (military), and much much more

This is so funny to me. Especially since Elon musk had to buy Twitter due to his tweets.