as importantly, given that Argentina and Chile share a border that Argentina thinks should be a lot further west than it currently is, Chile has about as much interest in a resurgent Argentina with a recent history of successful terratorial expansion under its belt as i do in Prison love.
which is to say, not much.
added to which, most of the LA countries backed Argentina in the 1982 war (their support falling short of actual help of course - but its the thought that counts), and they still hold a grudge against Chile for following its national interests, and not those of a tin-pot dictatorship they regularly had conflicts with. so Chile stays silent on the issue in order to avoid stoking up old fights which won't do its political inflence in MERCOSUR , and therefore its economy, any good at all.