We’re arguing at cross purposes. You are assuming the Constitution of 1789 changed the terms of perpetual union specified in the Articles. I am saying that because the new Constitution did not address those terms, the old terms remain in effect, unless a state joined with a qualification such as Texas. And the issue with Texas is whether the current state of Texas is the legal successor to the original.
Ultimately the right to secede is perpetual and remains a choice of the citizens of each state. I’ve heard yout theory before about the A-o-C and I am not buying it.