What does it mean to upgrade the same bed type according to the room conditions?

When you arrive at the hotel late and only stay for one night, the hotel has extra superior rooms. In this case, the room is empty anyway, so it is better to bend the rules and let the guests upgrade their rooms for free, which will bring surprises to the guests and help the hotel realize word-of-mouth publicity. Why not? 2. When the reserved room type is in short supply and there are spare rooms at the higher level, the hotel will upgrade for free in order to retain guests. 3. In case of hardware damage, ants or other accidents, the hotel will upgrade for free in order to compensate the guests.