Note that, as with ECO updates, the footprint will be changed only if pads match. I had one recently with a duplicated pad for some reason, had to delete the extra first (which was done by selecting the footprints, unlocking primitives, querying their pads, manually selecting every other pad in PCB List, deleting them, and re-locking primitives).
Another option is deleting the components, but saving their positions first by selecting them, and copying X1, Y1, Rotation columns in PCB List. Delete, import, select the new parts, and paste it in. If you want to save designator specs as well, make a copy of those data and paste it into a notepad or spreadsheet for temporary holding, then copy and paste it back in.
Tim