SO in recovery talks about "When he can"

My SO is an alcoholic. He was when we started dating but he hid it well until we moved in together. After dating for a short amount of time I got pregnant after being told I couldn't so neither of us expected it. He slowed his drinking down a lot to a point it was tolerable.

After the baby was born his drinking got way out of hand. He did some shady shit and I told him I wasn't putting up with it unless he got help.

He stopped drinking in Octoberish 2017 and started going to addictions counseling and we also started couples counseling.

Everything has been going great and I really felt like I was starting to trust him again and then he said this - "I'm only quitting for like a year so that I can control it".

What. The. Fuck.

We were out for lunch having a nice day so i didn't lose it I just kinda changed the subject. But what should I do?

He knows if he starts drinking again I will leave because he is not the type of person who can control it. It will get way out of hand fast.

Should I leave now even though he's working hard and hasn't even had a relapse?

I'm just kinda hoping that with therapy and time he will change his mind but I'm at a loss.

He is an amazing father to our 9 month old and I would hate to ruin the relationship over something that may or may not happen.