The words "secede" and "seceded" were terms of a later generation. The framers knew that the Constitution made the perpetual Union of the Articles more perfect, just as it says in the Preamble.
You know it too.
Walt
"I cannot but hope then, that the States which may be disposed to make a secession will think often and seriously on the consequences."
George Washington, Letter to Henry Knox, 17 Jun 1788, The Writings of George Washington from the Original Manuscript Sources, 1745-1799, John C. Fitzpatrick, Editor, V. 29.
So much for that allegation.
Perpuetual in law means that no express duration is defined, not that it is permanent. To make more perfect means to "complete" something. The Articles were abandoned, the several states seceded from it. The Articles were not included or incorporated by inclusion in the Constitution. Unless your version has a few extra sentences unknown to the rest of the world.
In Federalist 9, Hamilton urges for ratification of the new confederacy writes, '[t]he latter [the consolidation of several smaller States into one great Confederacy] is that which immediately concerns the object under consideration.' He discusses the advantages of this proposed union, then writes this, 'the confederacy may be dissolved, and the confederates preserve their sovereignty.'