Given how they tried pushing everyone away from 3.09, and then they wouldn't put it back up for a while when fences 3.10 released as a broken mess, I would guess there's some copyright issue, or an overlap with another product. Not sure how else you could justify pushing out a buggy mess then making it hard to downgrade. The beta forums were full of these complaints for MONTHS before release.
Before they incremented to 3.11 they had put up a modified version of 3.09 with some animation feature removed for some reason.
I have a setup file in my downloads from around mid September. It has no version number though.