Microsoft employees may also believe they are now becoming a nicer company. It would make sense to have that kind of internal communication, and it increases morale and productivity of you believe your work is positive.
Every large company manages public relations. That does not mean that they manage public relations dishonestly.If a company wants to turn their business model around, even if only out of self-interest, that is likely going to be accompanied by a PR effort.
There is no reason to assume malicious intent behind every PR-campaign because no institution benefits from lying out of principle.
And in the case of Microsoft, this turn-around seems reasonable. Their old, proprietary model isn't making them that much money any more. They're trying to be a developer-friendly platform.
Companies aren't people though; they're made up of people.
So, where you could make the argument that it's very difficult for people to change, the people who make up a large company change everyday.
There are likely many "good" and "bad" people in a given company for any definition of good and bad. I'm sure the people at any sufficiently large company don't even agree on what is good or bad.