"Is there any sound evidence that convinces us that Satan was not cast out of heaven long ago?"
How long ago?
If we check out the story, we can find clues.
Clue #1 The prophecy was written in the book of Revelation chapter 12, sometime during the first century, CE, therefore Satan could not have been kicked out of heaven prior to the prophesy being made?
Clue #2 John “by inspiration came to be in the Lord’s day...” Rev 1:10. reasonably indicating that the book of Revelation relates to the Lord’s day or the second coming of the Christ?
Clue #3 “A revelation by Jesus Christ, which God gave to him, to show his slaves the things that must shortly take place. And he sent an angel and presented it in signs through him to his slave John.”
Reasonably “the things that must shortly take place...” relates to the Lord’s day and beyond? Also since the scriptures were written for our instructions Ro 15:4 they would be written in words that we can relate to and understand?
Clue #4 In answer to the disciples questions “...when will these things be and what would be the sign of your presence and of the conclusion of the system of things.” Included in Jesus answer “...for Nation will rise against Nation...” Reasonably the Lord’s day would be around the time of “War Between Nations.”?
We may or may not agree that the Lord’s Day means the Lord Jesus Christ coming into his Kingdom?
Did Jesus come into his Kingdom in 1914 around the time of what has been termed The First World War?
Clue #5 “For whenever you eat this loaf and drink this cup, you keep proclaiming the death of the Lord until he comes.” 1 Co 11:26. So if Jesus came into his Kingdom in 1914, why are we still proclaiming the death of the Lord in 2022?
Above is just one example of the scriptures questioning the validity of the W/T’s claim that the Kingdom was set up in 1914. Still, Jesus did include in his answer to the disciple’s questions “Nation Will Rise Against Nation” Current events indicate that we are fast approaching such a conflict between nations, WW3?
Clue #6 Revelation chapter 12:1-9, shows that Satan is kicked out of heaven after the Kingdom is set up.
Which is around about now or in the near future?
So then, "Is there any sound evidence that convinces us that Satan was not cast out of heaven long ago”?
We need to make up our own mind based on how we interpret the scriptures?