I've found the ordonnance in question
Ordonnance du Roi qui erige en hopitaux d'instruction les quatre hopitaux militaire du Val-de Grace a Paris, de Lille, Metz et Strasbourg
[my translation]

We, Louis etc.
Having been informed of the motives which determined the suppression of the military teaching hospitals created by the ordonnance of january 1st 1747;
Considering that the hospitals have been of the greatest utility in providing a great number of distinguished military officers of health;
That it is principally due to this institution that the French military surgeons owe the great reputation which it enjoys, even among the foreigners;
Wishing to give a proof of the personal affection which we bear to the brave men who compose our armies and who contract illnesses or receive honorable wounds in our service;
On the report of our minister Secretary of State for war,
Have ordered and are ordering as follows:
Art 1 The four military hospitals of Val-de Grace at Paris, de Lille, Metz et Strasbourg are established as teaching hospitals.
Art 2 ...[ goes on to detail the staff needed for each hospital]

Not particularly helpful in that it doesn't say what it is replacing.

Susan