That is a rate limit. That user was probably abusing something and trying to scrape github and got hit by a rate limit. Or someone in their house/flat/building did. There is just not enough in that post to tell what the hell is going on and it is far too early to jump to the concluding that github has done something wrong here.
They might have lowered the rate limits, they might not have. I doubt the lowered it to 3. Something else is very likely going on. We have to stop jumping to the worst conclusion anytime anything happens and imminently knee jerk reacting to that idea. We can wait for more information to come through and see what the actual issue is before assuming the worst.