The ATPL makes you eligable for the Eurowings Group (Germanwings, Eurowings Germany/Europe etc)
For this course the selection is done by interpersonal
The MPL still uses the DLR Tests as this is a requirement to join Lufthansa Mainline. It also allows you to join any other airline in the Group such as Austrian, Swiss, Cityline and also the whole Eurowings Group.
Where on the other side with the ATPL if you wished to join any other LH Group Airline outside of the Eurowings Group (Austrian/Lufthansa/Lufthansa Cityline/Swiss (swiss has for ready entries their own selection) you would need to re apply as a ready entry and re do the DLR Assesment.