Not in the sense that matters here: the caller doesn't pay (unless the call is frivolous), leading to more calls that are preemptive, overly cautious or for non-live-threatening cases. That behind the scenes people and equipment are paid for and a whole structure to do that exists isn't really relevant here

> Do we think paramedics in Germany are more susceptible to PTSD

No, we think that there are far more paramedics than ICU or ER staff, and helping them in small ways is pretty easy. For ICU and ER staff you would obviously need other measures, like staffing those places with people less likely to get PTSD or giving them regular counseling by a staff therapist (I don't know how this is actually handled, just that the problem is very different than the issue of paramedics)