As parisATCO explained CDG has 2 different strategies for sequencing:
-Anticrossing (MERUE and LORTA on the north runway/ BALOD and OMAKO on the south runway)
-Minimum taxiing time (runway choice depending on the company to have a short taxi time)
Sometimes they change runway if there is space on the other. That 's why Paris ACC can't tell you for sure your runway before the IAF.
Inner runways are used for departures as they are longer. But if you are heavy you can ask for them for landing. CDG is flexible when they are not busy.