IMO all of them would - and did. They added verbiage to ease concerns of nervous citizens but they agreed to the Perpetual Union and later the More Perfect Union.
They all knew that the alternative was to go it alone - a circumstance that would surely culminate in being subsumed or consumed.
Are you suggesting they didn't mean what they said? Say anything to get it ratified, then go back on their word? If so, you have a pessimistic view of those key founders. Even George Washington recognized the new union was not the old union. [Source: the records of Congress, August 22, 1789, Link, my emphasis below]:
The President of the United States came into the Senate Chamber, attended by General Knox, and laid before the Senate the following state of facts, with the questions thereto annexed, for their advice and consent:
... "As the Cherokees reside principally within the territory claimed by North Carolina, and as that State is not a member of the present Union, it may be doubted whether any efficient measures in favor of the Cherokees could be immediately adopted by the general government ..."
The Constitutional Convention of 1787 basically ignored the Articles of Confederation and wrote an entirely new document outlining a different government governed by the new Constitution, not one governed by the Articles of Confederation. I hold, as Washington apparently did, that the new union was indeed a more perfect union, but not the same union or one with the same rules as the old union.
If the Constitutional Convention had wanted to say the new union was perpetual like the old union, they could have said so. They didn't. They started forming the a new government after nine states ratified the Constitution (Article VII of the Constitution) instead of waiting for the unanimous consent of all thirteen like would be required under the Articles. They treated the Articles and its perpetual union as a dead letter like the perpetual union of New England colonies formed long before the Articles.
I also found the following in the records of the first Congress:
And be it further enacted, That all rum, loaf sugar, and chocolate, manufactured or made in the states of North Carolina, or Rhode Island and Providence Plantations, and imported or brought into the United States, shall be deemed and taken to be subject to the like duties, as goods of the like kinds, imported from any foreign state, kingdom, or country are made subject to.
Those two states had not yet at that time ratified the Constitution and were not members of the new union and their specified goods had to be imported into the United States.