My husband planning to leave

My sister is living with her husband in his family's home along with his parents. They used to have many issues between them mainly due to parents' and his sister's interference. Things were not going well but my sister adjusted a lot since she loved him but he never made any efforts and used to gossip and taunt my sister along with his family. Recently out of surprise her husband suggested that they move out and live separately in a rented flat so that issues get resolved a bit. My sister was very happy and surprised that finally things are going to get better. But little did she know that the real reason was that he had got an opportunity to go abroad from his company and he wanted my sister out of his house without any trouble. So within a month after they moved in, he informed her that he got H1B visa and so he will be going and he left. Looked like all of this planning and moving to a new place was just to get her out of his house. He has literally deserted her. He says when he comes back then we can see if this marriage works out or divorce.