I mean polpo's stand was killed too, but he was alive

I think he can still use it

I think Hazamada's stand is a stand that is bound to a mannequin, mainly because non-stand users can see it, so the mannequin it was bound to was destroyed, but Hazamada could probably get another one and bound Surface to that one.

Thrpyke actually answered it the way I would have.

Super late but technically no, he is a still a stand user but his stand was rendered useless since it was a bound stand and the thing it was bound to was destroyed, its also an automatic stand, thats why the damage was not transfered to hazamada when destroyed

I think JoJo did say something about Stand abilities healing or something. So currently his stand is useless, but if he sees intense character growth, it's possible that his stand could reawaken again in another form or for another use. Rohan's stand seemed to be a Bound Stand until later on. It's possible he may see his Stand recover in some capacity, but it would require a new manga I think.