Why are you assuming that someone who sensibly refrains from overly impulsive behavior wrt. showing their emotions (this is what "self-monitoring" ultimately means: we all do it in all sorts of social contexts, and it's a normal part of being a healthy, well-adjusted person) must necessarily be "disconnecting" from them altogether and lacking in emotional resilience?
If you manage to "self-monitor" all the time, and never show more than a modicum of vulnerability, that seems very disconnected to me.
Perhaps 'disconnected' is the wrong word, but what I mean is that emotionally healthy people feel their emotions and express them, not just hold them at arm's length and pick and choose which to feel and express.