I doubt that.
The pineapple is literally made for intercepting traffic, so yes it can perform MITM attack, but the traffic you are talking about is encrypted and i doubt anything on the pineapple can decrypt it, so no you cant steal their creds that way.
Yes you can grab the information and "track down" the AP, or deauth people from it, but (or tell them)
The best thing to do here is to put restrictions on the computer,(or just let them use the internet freely)
You cant hide radio waves, you will still be able to see the BSSID (MAC of the AP)