John Doe "has added new links and updated their profile"
John Doe is an individual. "Their" is plural. I understand they're trying to avoid "his or her", but I'd prefer it.
Another example... when someone requests an endorsement, the message comes across as "Can you endorse me?".
The word "can" implies ability to do something, not willingness. I'd much prefer to see "Would you endorse me".
There. It's off my chest now.