With regard to this short article, it is NOT saying that at the time of John’s vision there is already a raptured Church. Neither can the 24 elders represent the nation of Israel because that nation has not yet been redeemed. Since Got Questions maintain that the tribulation (seven and a half years) comes before the rapture of the Church, and since both events are still some time future, then the identity of the 24 elders is still unknown. The article says that the 24 elders are “most likely representative of the Church” and that they are not angels.
I agree that the penultimate sentence is confusing because it sounds like the Church has been raptured and that the 24 elders are already wearing the crowns of victory and they are in heaven ruling alongside Christ Jesus. However, rather than speculate, I will contact Got Questions and ask them to clarify.
With regard to Got Questions doctrinal basis:
We are Christian, Protestant, evangelical, theologically conservative, and non-denominational. https://www.gotquestions.org/about.html
With regard to Got Questions and Calvinism:
It is interesting to note that in the diversity of the body of Christ, there are all sorts of mixtures of Calvinism and Arminianism. There are five-point Calvinists and five-point Arminians, and at the same time three-point Calvinists and two-point Arminians. Many believers arrive at some sort of mixture of the two views. Ultimately, it is our view that both systems fail in that they attempt to explain the unexplainable. Human beings are incapable of fully grasping a concept such as this. Yes, God is absolutely sovereign and knows all. Yes, human beings are called to make a genuine decision to place faith in Christ unto salvation. These two facts seem contradictory to us, but in the mind of God they make perfect sense. https://www.gotquestions.org/Calvinism-vs-Arminianism.html
With regard to Recommended Resources: The views expressed by Got Questions in the body of their articles are often a summary of various views on that subject. Some Got Questions articles give a recommended resource, but what they say in their article may not be taken directly from the book they mention. I have written several articles for them and I can assure you that the recommended resource was not consulted by me, neither was any part of it quoted in the article.