I’m not going to say that John’s Revelation doesn’t contain any doctrine, but that doctrine is not the purpose for writing it. It is prophecy in symbols, all reaching back to echo the symbols of the Old Testament. Its content does not fall under the purpose of this study.
Our purpose in this study was to show fairly concrete statements in Scripture that point out the continuity between the Old and New Testaments. Not so much in the particulars, but there is a clear continuity in assumptions and expectations of how God works and what He requires of us. The Scripture flatly states the Gentile believers are not bound under any particulars of the Law of Moses, but then references fundamental concepts of morality behind that law.
I have made my case. You can decide whether any of it matters.