FWIW, I just flew MUC-IAD and got switched from a Polarized 772 to a 3 class IPTE one about 3 days out. Everybody seems to have been auto reassigned (no empty seats right after the switch) and I got reassigned from 9G (middle aisle) to 9C (middle aisle).
This suggests that they try to keep you in the same location, which implies that Rows 1-2 might get moved to the old F seats. But I'm just one very inconclusive data point.
I'm 11 D & G right now in Polaris so I'm worried that if the switch happens I'll end up in the middle in the back if your logic holds up
