This is another example of corporations and employees trying to figure out this new world. It's gonna be rough for a while.
Before LinkedIn and back when Facebook was still only for college students, my wife had a blog where she tangentially mentioned work. She was reprimanded and put on the CEOs crap list for that (later fired directly by the CEO after, weirdly, getting a glowing review from her direct supervisor).
Now that kind of sharing is normal. So many of our corporate bureaucracy want to go back to the 50s when they had full control over messaging, but that's just not going to work going forward. It's gonna take a while to get to a good middle ground, with some people kicking and screaming on both sides.