Queer jams make it to onto the calendar all the time, and are fairly common. I think I’ve seen anti-capitalist jams on the calendar too, but I can’t find any right now, so I’m not entirely certain. A connection to Cuba could be problematic, not because of any political stance on the part of Itch.io, but because of the embargo.
But the more likely explanation is that the topic of the jam is not the problem. Other jams with completely different topics have also failed to make it to the calendar.