Sorry, but 2 Pt. 3 is in obvious reference to the Flood of Noah:
"Whereby the world that then was, being overflowed with water, perished:" (2 Peter 3:6; cf. 1Pt. 3:20)
The pope might have said or meant the beginning of the Bible, while i know of no official RC teaching that describes your interpretation. Not that Rome is the standard for Truth,
Not necessarily the Noachian flood referenced there. God doesn’t create in vain, and since “was” in Genesis 1:2 should have been rendered “became” (as in Genesis 19:26), take note that there was no dry land after the world “became” this wasted state in Genesis 1:2.