This is a good question. Article 1, Section 10 does not apply in regard to secession because by the act of secession, the separating entity is no longer bound by the compact.
Secession does not need to be spelled out in the Constitution for it to be valid. Certainly, an explicit recognition of the right to secede would have been helpful, but though all contracts are designed to be perpetual, they can be canceled by one party or the other. And the Constitution is nothing more than a contract or compact “between the States so ratifying the same,” not the people of the United States, but the people of the States in convention.
Moreover, the Constitution did not alter the nature of the “Union” as under the Articles. It was designed to make it “more perfect,” but not subvert the standing of the States in the Union, at least that is how the conservative faction led by Dickinson, Rutledge, and Sherman viewed it and how it was sold to the States in the separate ratifying conventions. Jefferson declared that there were thirteen free and independent States in the Declaration. Nothing had changed by 1787 and the Constitution did not change that either.
Remember, powers are “granted” in Article 1 and “delegated” by the 10th Amendment (the first proposed amendment by virtually every State). Granted and delegated have meaning. A granted or delegated power can be rescinded by the granting party which had the power or authority to grant it in the first place, i.e. the States who created the compact.
Additionally, as the Preamble states, it is a “Constitution for the United States of America” not “the United States Constitution” or the “Constitution of the United States.” Again, for and of carry different meaning. For is a plural term holding weight only for the Union of the States; of implies possession in the singular, or the United States as a single State.
Hope that helps.