I currently generate a list of the feature classes in a gdb using a submodel with a feature class iterator and use Collect Values to make a multivalue list of the fc names.
My problem comes with trying to send the list to Conversion Tools-->To Shapefile-->Feature Class To Shapefile (multiple) as it only accepts Feature Layers as input. I am unable to figure out how to manufacture multiple feature layers from the Collect Values output parameter from the submodel.