I will be making chicken pot pie for about 350 people at a conference, but I'm making the filling separate from the biscuit topping. The plan is to serve the pot pie in a disposable container, topping with a freshly baked biscuit just before serving. My question is this: Is there any reason to bake the hot filling, which is fully cooked already? Does it improve the taste or texture in any way?
Good pot pie has a layer between the biscuit or pie crust and the filling. That layer is goopy, it takes on properties of both of the other elements. Without that kind of middle layer, the two elements would be missing that unifying texture. That said, it's not a big deal. Just be sure that the ingredients in the filling are truly optimally cooked.
If the fresh biscuits can live on the filling for even a little while, that will help that texture issue.