Yeah, this one is too nebulous to answer one way or another. There’s too many possibilities involved to get to a point of certainty.
It is definitely possible for sure. But so is a simple desire for human contact, friendship, or just being bored while waking. Could be looking for friends for his dog.
It’s even possible that the guy read your smile as nervousness and is trying to alleviate that so neither of you has to change when/where you walk the dogs. Could be similar, but wanting to help your dog not feel nervous around him and his dog.