What to Do After You Get Out of Drug Rehab?

What to do after you get out of drug rehab?
so my boyfriend is getting out of rehab in 2 weeks… and i guess his parents plan is to send him to live with his dad. the only problem is, his dad isnt such a great person, when he was young he mentally and sometimes physically abused him. his dad is one of the srictest people i have ever met, and when my boyfriend is over there he feels completley uncomfortable and wont even talk, he is terrified of his dad, and does not like him as a person at all.. and from what ive heard he plans on pretty much keeping him on lock down for the most part, like not letting him go out and do things with friends or just things in genral i guess… what do you think about this idea?

before he went in he lived with his mother and shes great, shes very loving, but not as strict as his father , but she could be now that hes out,shes very helpful when it comes to listening to him ad helping him out. he feels very comfortable there and is pretty close with her and can talk to her, but would it be bad to go back to where he lived before he went into rehab, im pretty positive that he wants to go back with her and not his dad..should he choose where he goes?
he is 22 years old with a good job.