Yes chins are social, but they are like humans, not all chins get along with all other chins, and some prefer to be alone. I guess it also depends on what your plan and situation is too. Are you looking for a cage and playmate for your current chin? or are you ok with it ending up just another chin in the same room?
A few things to think about off the top of my head include...
1. Chins are herd animals, so even another chin in the same room can help make them feel less alone and give them someone to chat chinchilla too. If they get along then all the better, he has someone to keep him company when you aren't home, to cuddle up and sleep with, and basically someone to watch his back so he feels more secure.
2. Do you have the money, time, and space for a second chin? It's best to quarantine new chins in a separate room for a month so that they can settle in, and for any illness to show up before exposing your current chin to it. Also if things don't work out do you have the space for a second cage and time for two individually?
3. Chins can get jealous, but it's complicated, kind of like having a second child. If they become buddies then he likely wont end up feeling upset. However if they hate each other he could get mad that you got a second chin. Also if they don't get along would that mean his playtime would get cut short? Would he be getting any less of your attention and time?