Why are keys in the right side of the keyboard (high keys or treble) sustained even when the damper/sustain pedal is not pressed?

On an acoustic piano and also in some electromechanical pianos, if you release the keys or release the damper pedal while playing, the sound stops because the dampers press down on the strings stopping the sound immediately. However, dampers are not used in the highest region of the keyboard, because the strings there are short and their sound attenuates quickly. Therefore, the sounds of highest notes linger even after the keys are released. Our instruments are designed to reproduce the sound of the original instruments as faithfully as possible, down to the smallest detail.  So, if the original pianos works like that (for example Electric Grand, Acoustic Piano and others), also our sounds (especially id based on physical modeling) works in the same way.