I'm not sure if it was, but John XXIII implied in his Humanæ salutis (25 Dec. 1962) that Vatican II was not a reconvening of Vatican I:cf. Vatican II was convened explicitly against Vatican I
I see what you are saying, but logically, it could be construed either way --- if we were to admit the possibility (and yes, this is
really "reaching") that one council can be suspended, another council can then be convened and ended, and then the first council could be resumed. A "council sandwich", if you will. Is that even possible?
As a practical matter we will probably never see "Vatican I" resumed. But you never know. As another poster said, Our Lord works in mysterious ways. Look at the "loophole", if you want to call it that, that resulted in the Church having to acknowledge that
Quo primum was never abrogated. I for one didn't see that one coming either (but I'm glad it did).