@Mr. Bond Please note that in the article that you cite from the JW.org website states,
Commenting on this section of Revelation, Professor William Barclay wrote: "Things are set down without any apparent order; . . . and it is often very difficult to be sure who is the actual speaker.” (The Revelation of John, Volume 2, Revised Edition, page 223) Thus, “the Alpha and the Omega” at Revelation 22:13 can be identified as the same Person given this title elsewhere in Revelation—Jehovah God.
The article is using the statement that "Things are set down without any apparent order" to further reiterate that no one knows for sure who is actually speaking. And for that reason the article says,
“the Alpha and the Omega” at Revelation 22:13 can be identified as the same Person given this title elsewhere in Revelation—Jehovah God.
So they are making a logical conclusion based on other scriptural evidence and not making a supposition based on a whim.
Incidentally Barclay is frequently quoted by JWs. In fact a quick search of his name on Watchtower Libray comes back with 37 occurrences. While true that he identified the speaker in Revelation 22:13 as Jesus it is also true that he says it is difficult to be sure and also true that Barclay said Jesus is not God.
This begs the question: How can Jesus be identified as the Alpha /Omega by Barclay on the one hand and be said not to be God on the other? JWs consistency identifyconsistently identify Alpha/Omega only as Jehovah God.