So I did another test.
I braised my short ribs in a 250F oven. After 1 hour I checked the temp of the braising liquid and it was 210-212F!
I braised my short ribs in a 200F oven. After 1 hour, I checked the temp of the braising liquid and it was 195F. After 3 hours, the temp of the braising liquid was still 195F.
So if you really want to braise low and slow, it needs to be done at 200F oven or lower. Otherwise braising in a 250F oven is the same slow boiling the short ribs on a stovetop.
Please note, this is assuming that the ribs are completely submerged in stock/braising liquid, and you get the stock to a boil, before you put into the oven.