Debouncing using capacitor+schmitt trigger(which even has hysteresis response graph drawn on top) is no doubts a hysteresis. But I wouldn't call all debouncing

Debouncing using capacitor+schmitt trigger(which even has hysteresis response graph drawn on top) is no doubts a hysteresis. But I wouldn't call all debouncing strategies a hysteresis. One (easy to implement in code) debouncing strategy is lockout - after the first input transition perform the output change immediately and then stop reading any new inputs for some time. This has the benefit of having no delay, but downside is that it amplifies random noise caused by other factors when the switch isn't moving.