What is significant about this verse is that it is ostensibly negating the very foundation of Buddhism. These are the Four Noble Truths that are negated!
What does that mean, for a major religion to apparently negate its own tenets? I think understanding this verse is the key to understanding the manner in which the Sutra is asking us to change our viewpoint. It isn't saying that the 4NT are wrong. It isn't saying that they were never declared, nor that they are not Truths. That would be absurd, especially since they are the basic teachings from which all else in Buddhism flows.
It is saying that the manner of all the various negations in the list is not mere nihilism. It is not saying that all that stuff, all those categories, don't exist. It is saying that we need to change the way we think of their existence. Like all those categories, they are not solid objects to which we could cling. They are creations of the mind, referring to the shared illusion we call objectivity. Like all those other categories, they have their uses when dealing with so-called objective reality, but ultimately, they are only expedients.
When they have served their purpose, we can let them go. If we can do that with the Four Noble Truths themselves, then we can do the same with all other categories.
Om mani padme hum
Kathy