I see what you’re saying, but I wouldn’t phrase it quite that way. If we’re in the Matrix, then that changes the truth of the following propositions: “what we perceive is spatially represented in reality,” and “the cause of our experience is the external world impinging on our senses — i.e. I see a table because there are real bits of matter which are leaving an impression on my senses.”
Other than that, I think I generally agree with you. Even if everything is a hallucination, whatever we experience still has some kind of true, reference-able, meaningful existence.