As far as I understand and what has been discussed in other posts, no, there is no way to prevent this.
As you noticed, Itch does not inform you if your game is quarantined, so uploading it privately first would not do you any good, because you would not know if the game was approved or not.
Also, not knowing the algorithm, we also do not know if it is influenced by users, for example, a sudden increase in downloads, maybe a group of people reported it, etc.
I understand how frustrating it is if you are a legitimate developer, but without data from Itch I cannot say if the measures are good or bad.
I assume that they do not inform you to prevent bad actors from automating processes that seek to break Itch's system and I assume that the cases of false positives will be a small number compared to the benefit they bring.