Hotel works no problem, they will honor reservations already made (but not points booking), for how long is unknown.
But points and nights are not added and as for benefits, they will probably give something like access to the club lounge but I wouldn't count on any real benefits from them. You need to show your satus at Marriott app.
The owner of the building, LIM Center sp. z o. o., is reportedly negotiating with Marriott what to do next