My guess is that you'd get called into the backroom by the elders after the meeting. They would probably ask you if you're having difficulties or if you've committed some serious sin that they can help you with. They will try to dissuade you from actually disassociating. They will try to convince you that this is the truth, etc. If they succeed in "convincing" you and/or they realize you don't really want to disassociate, then they'll probably announce at the next meeting something along the lines of "a matter involving bro. so and so - who is still one of Jehovah's Witnesses - is being handled by the elders". If they fail to convince you to not disassociate, then they'll announce: "bro. so and so is no longer one of Jehovah's Witnesses." (because you obviously don't have the right to announce your disassociation yourself, without their final says so)
But it would be an epic way to disassociate yourself - one that should be captured on video or audio. It should not be done in a somber way but an exciting way. "We have some good news: Bro. [my name] has escaped the clutches of false religion as he's proudly no longer one of Jehovah's Witnesses! [or "Watchtower's slaves"]"
And don't consent to meeting with the elders afterward. Your decision is final and yours alone. You ceased being a member when you made the announcement. They have no authority to meet with you to try to dissuade you from making a decision which you've already made without needing their permission.