in_memory can store/display simple formats. There is no reason this cannot be updated to file geodatabase level storage. ...My line of thinking: If a shapefile (A series of files) can be used as the format structure then data within a file geodatabase should be no different to model for in_memory. Think of the process functionally similar to copying a dataset from one database and pasting it into another (This keeps field names/aliases/domains/etc.) except we would be moving/creating/temporarily storing the data in memory.