Received a few requests to follow MR on Instagram, with the reward being points - I believe 500, though I can't recall. So, over a week ago, I did as they asked. I have since received tons of messages on Instagram from MR, but no points.
The promotion was released to Insiders on June 13. If you followed that day, it was 1,000 points. The rest of Marriott Rewards members received the e-mail June 14, and it was 500 points. According to the T&C, points will be deposited within 4 weeks.