I'm not sure. I haven't researched it and don't know if anyone's done studies or anything (can't really think of the governemnt giving out grants to unlock the secrets of chinnie winks hah). But thinking about it, if they were to wink in a communicative way, I'd expect to observe it between themselves (chins winking at chins) as well. I would first rule out an irritation in the chin's eye.
I don't want to ruin this warm fuzzy vibe going on--I'm just saying I think many people anthropomorphize animals to an insane degree. Animals are amazing and make people feel wonderful. The idea that chinchillas may not be able to feel "love" shouldn't change that. As with anything, I'd make sure it isn't something bad like a medical problem before coming up with other especially adorable scenarios.