Well, let's see:Is there any other vision in Revelation where John was shown a vision of something that had already happened?
Rev 4:1 (NWT) says:
After this I saw, and look! an opened door in heaven, and the first voice that I heard speaking with me was like a trumpet, saying: “Come up here, and I will show you the things that must take place.”
So, if one were to take these words as referring to John only seeing things that were to occur future from then (mid-90s CE or thereabouts), then, everything John sees from here on in the Revelation must be something that only occurred future from then. So, let's see if that strictly 'future only' view holds up:
- Rev 4:2-3, John sees someone seated on a throne. Is this future only? Or is this something He has always been doing? If one takes Rev 4:1 as having to mean only future from when John receives the Revelation, then, this is something God only started doing since about the mid-90s CE or afterwards.
- Rev 4:8 has the four living creatures saying "Holy, holy, holy ..." Is this something they only do future from when John sees the vision? Or have they been doing this for a long time before this? (Isa 6:3)
- Rev 4:9-10 "And whenever the living creatures give glory, honor, and thanks to the one who sits on the throne ..." Only future from mid-90s CE? Or have they been doing this for a long time already?
- Rev 5:5, 6 "Look! The Lion of the tribe Judah ... has conquered ... appeared to have been killed." Future from mid-90s CE?
- Rev 5:9, 10 "... because you were killed and with your blood you have purchased for God persons ..." Something that happened future from mid-90s CE?
- Rev 6:2 "... and here came a white horse! The one who rode it had a bow, and he was given a crown ..." Col 1:13 has Jesus with a kingdom, implying he already was crowned. Heb 2:9 has Jesus then presently with a crown (early 60s CE?). See also this post for other scriptural evidence that Jesus was crowned upon his return to heaven.
- Rev 6:9 John sees the souls who had been violently killed because of the Word of God and their testimony. Only after mid-90s CE? I think Stephen would disagree. (Ac 7:58-60)
- Rev 12:1 'A woman clothed with the sun and with the moon under her feet and a crown of twelve stars.' As someone already mentioned, the description is drawn from OT imagery of Israel. Constable's Notes comments:
In view of Old Testament imagery (cf. Isa 54:1-6; Jer 3:20; Ezek 16:8-14; Hos 2:19-20) and the following reasons, the “woman” seems to symbolize the nation of Israel. She wears a crown (Gr. stephanos) with the sun, moon, and stars, as God pictured Israel in one of the nation’s early symbolic representations (Gen 37:9-11; cf. Isa 26:17-18; 60:1-3, 20). There are many figurative references to Israel as a travailing woman in the Old Testament (Isa 26:17-18; 66:7-9; Jer 4:31; 13:21; Mic 4:10; 5:3). She eventually gave birth to Christ (Rev 12:5). In Genesis 37:9-10, the sun corresponds to Jacob, the moon to Rachel, and the 12 stars to Israel’s 12 sons. [End of quote]Mt 21:43, Gal 6:16, Jas 1:1 & 1Pe 2:9 could be used to show that the imagery of the "woman" of Rev 12:1-3 as Israel can be extended from Israel under the Law Covenant (which produced the Messiah, that is, the "child" of Rev 12:5), to also across the Christian era under the New Covenant (which produces the woman's further offspring - Rev 12:17; Gal 3:25-29).
- Rev 12:4a "... the dragon's tail swept away a third of the stars of heaven and hurled them to the earth." I take this as a reference to what happened in Gen 6:1-4. I think you take this differently if I remember correctly. (See here.)
- Rev 12:4b ''The dragon kept standing before the woman to devour her child.' I take this as describing efforts by Satan to prevent the Messiah during all the time of the nation of Israel. All of which would be prior to mid-90s CE.
- Rev 12:5 'The child is born and caught away to the throne of God.' Which I take as a reference to Jesus, his ministry, sacrifice, and glorification. All pre-90s CE. And for the reader, see the discussion of this above (here).
- Rev 13:2 The dragon gave to the beast his power, his throne, and great authority to rule. This was something already claimed by Satan back in about 29 CE. (Lu 4:5-6) (And see the last two paragraphs of this post below.)
- Rev 14:6, 7 An angel has good news to preach to the whole world, with the message to repent. Acts 17:30-31 indicates this was already going on (mid-50s CE). It continues past the 90s CE. But it started before that. (Mt 28:18-20; Ac 1:8)
- Rev 18:24 "In her was found the blood of prophets and of holy ones and of all those who have been slaughtered on the earth.” That sounds like it covers across many centuries before mid-90s CE.
Well, that's my tally of things that had already happened, or had already started to happen, before John received the Revelation, and before he was told what was said in Rev 4:1. Although, somehow, I don't think we will end up agreeing to anything. Yet, I am glad to have these things cataloged, even if piece by piece.
Just as an aside for the reader, since Rev 13:2 and Lu 4:5-6 have been mentioned above: See the main articles # 3, 6 & 7 linked to in this post in connection with Satan's statement to Jesus (in Lu 4:6) that authority over human kingdoms had been "delivered" to him, as well as discussion of the "appointed times of the nations" referred to in both Lu 21:24 & Ac 17:26.
Rev 13:1-2 has the correct order of events: Where the beast appears first, and then the dragon gives it great authority. This corresponds with Satan telling Jesus that authority over human kingdoms was "delivered" to him, implying that some form of human kingdoms already existed before Satan began 'giving it to whomever he wished.' In Rev 13:1-2, the beast first arises, then the dragon is said to grant it "great authority." In Genesis 10, human kingdoms first start appearing, then, only after the Tower of Babel incident (Gen 11:1-9; De 32:8), does the first world power (Egypt) appear. The implication being that the Babel incident is the point in time when human kingdoms were "delivered" to Satan; God using a 'divide and conquer' method to 'deliver' them.