I hope you keep going to those meetings
Whatever the addict needs, they have to decide that for themselves. It's easy for us to see what they need but us telling them won't make any difference if they don't want it themselves. Your son, fresh out of rehab, knows what he needs for his recovery and how to get it. If anything, perhaps remind him if he asks for your help.
Freedom mentioned boundaries and they are so important! I used to ask my daughter if she was going to meetings or needed one, but that was still me trying to control her. Once I established personal boundaries, I would let her know when they were being violated and consequences followed. They were not punishments, they were self protective measures. There have been several times when she's been asked to leave my home, then contact me when she's ready to respect those boundaries.
My boundaries started off being about drugs, but soon became about behaviors with everyone in my life, not just her. I no longer focus on her addiction or recovery, I focus on my serenity. If she's compromising it I let her know. She has the choice, as does everyone in my life, to either back off or one of us is taking a hike. I no longer allow it to get the point where I'm suffering.