No, it means he's not freaked out by the idea of having kids period. Unless he's specifically talking about having children with you and more broadly, your future together, he's just speaking his mind. He likes kids and thinks about his future children.
Now, understandably, having a conversation with another person about future children might seem to indicate that this individual is thinking about kids with you, but the truth is, it doesn't.
I guess a parallel I could draw is how many women have their entire weddings and stuff mapped out. I don't know that I'd assume that because a woman I'm seeing tells me about her wedding plans that she'd automatically have me in that role. Sure, she might, but I wouldn't assume it. Same goes with dude and the babytalk. It's wholly possible that he's not freaked out by kids with you, but you'll only know if you ask - which I'm not exactly suggesting you do.
In fact, I suggest you just let him keep on going with it and wait for him to ever bring it up to you. Maybe he will, maybe he won't. Just chill until he does and tell him the names you like.
If a guy wants to have a baby with you he will tell you. If he doesn't say that than don't assume that he wants to. At least not yet.