This may differ between countries, but locally - knowing a specific app exists. A clinic buys software that fulfills the requirements and knows nothing about the license. As long as someone can install it, operate it and provide support, it can be literally anything.
As long as the decision makers know something is available and actually provides value (and the decision makers are not stubborn and set in their ways for decades), it will be implemented.
Caveat - people writing most medical/billing software don't have any incentive to release it as FOSS and they have more money for promotion than any FOSS project.
In healthcare one should be very strict about who gets to see patient data. At least our healthcare laws say that only healthcare personnel involved in the care of a patient can see health information of that patient
So one cannot use e.g. slack channels to shout to everyone about some problem. The usage pattern should be closer to email or an issue tracker with only involved doctors and nurses added to each patient or case. Email is of course unsuitable because of how easily information can slip out unprotected.
Unfortunately, doctors are people like the rest of us, use whatsapp and facebook to ask thousands of colleagues for help with their patients. Totally against the law.
