It is just playing the right card at the right time. It fails on the other side expect to be approached. It doesn't make sense he has gone back to his ex and still want open communication with you. The social media act as evidence he's still with you.
I wouldn't think it's wise to accept him back to your life when he comes. Why does he want to communicate with you when he is another relationship? Again, why say you asked for a breakup when you didn't.
He will come when it doesn't go well on the other side. Social media acts as a channel to convince his friends he's still with you because of liking and commenting to each other's status and so on.
Please think whether it'll be alright to have h back when he comes back. You need to reflect and arrive at a desirable situation whether to go move on with your life or not.