Sort answer is yes.

The DKT3220-SD are virtually the same as the DKT3220-SD except for a small cosmetic change.

The 3000 series will work like 2000 series phones when connected to the old Toshiba systems, so you can use these phones on a DK280. The display will be a little shorter then the DKT3200 screen and the speed dial button is not functional, just like the DKT2000 series.