Stress? Absolutely and without doubt I'd be stressed in addition to grieving!
He has to think about supporting his family now that the main earner is gone. I don't know the urgency of that; I'd like to think there was not only life insurance on each parent, but business insurance, also. Business insurance exists for this reason among others- the death of a principal. I have no idea if they had savings, investments, life insurance, business insurance, mortgage payments, car payment, office rent, staff wages, utilities, food...
Absolutely stress! I understand wanting to get the practice back up and running because for one thing, everything is already in place but for lack of an MD. To me, it makes sense. I know TS was the heart and soul of that practice, but for practical purposes at this moment, another doctor is needed.