Of course, that is the requirement! But in the end, everyone can decide for themselves whether they place the glass plate or not. We also have oak floorboards, and the glass plate is standing in the storage room. The fireplace is closed during operation and is only opened to add more wood; I almost believe it is impossible that such a spark flight occurs that something happens.
Our chimney sweep/fireplace installer also said that the plate is necessary for approval. But what you do afterwards is up to you. By the way, our fireplace is rotatable (180°), but the plate is only an L shape, so you would always have to rotate it as well, and it only covers an area of 30-40 cm. As I said, the important thing is to only open the fireplace carefully; then no sparks will fly, and in the case of a bigger incident, the plate would hardly offer any protection.