Another theologian from your list of "late daters." Do you agree with Ewald when he said this?:
‘That the Apocalypse was not written by the same hand which wrote the Gospel and the Epistle, is clear as the light of the sun.’--G.H.A Ewald
Ewald et. al. from your list also cast into doubt that Moses did not write the Pentateuch, nor Daniel his prophecies, nor the Evangelists the Gospels.
I am sure you do not agree with them, however, you must see a motivation.
"That the Apocalypse was not written by the same hand which wrote the Gospel and the Epistle, is clear as the light of the sun."--G.H.A Ewald
I really don't know that much about the debate. I know from the beginning there were questions about the authorship of the Revelation. It seems an entire industry has sprung up around the Johannine Authorship debate; though not nearly as large as the "Who Will Be The Next Antichrist?" debate that has created the massive Dispensational Industrial Complex, with their incredible book and movie sales.
Philip