Here is the suggested process (you can accomplish this in either 2.9+ or 3.0):
Drag MetaData (or File Attributes) block and point it to the folder with files.
Use Sort block to sort on the Date field, using descending order
Add Record filter, where Record number =1
Use Batch Append block and point it to the same folder. You may wish to narrow down the search by using the asterisk functionality, so only pick files that contain certain word e.g. "sales" or have .csv extension. Tick the option to create a source field without the extension.
Merge the two branches on the Filename.

Here is the workflow online
http://ec2-54-89-54-249.compute-1.amazonaws.com/Import%20Latest%20file.iox/