I reckon. But its drawn what it needed from the fan leaves, which is part of their function. I also reckon that there are worse things than a mild N deficiency when you're almost at harvest.
The reason I do this is because in the past where I kept using the bloom its happened that I've gotten purpling of my leaves in late flower, indicating a PK deficiency, the last thing you want in late flower. I knew there was PK in the reservoir, I knew the Ph was right, and I didn't want to raise the PPM any higher. So rather than adding a lot of PK, I stopped adding N. Seemed to work as I wanted. So maybe not technically a flush; just altering the NPK ratio.
Whatever just my experience not looking to argue...