Having a UY that falls right before your typical travel offers the most flexibility in what you can do with points if you have to cancel a trip, want to change a trip that will use less points, or are using borrowed points.
Since you bank current UY points for use in the next UY within the first 8 months, traveling during this timeframe can be good.
Of course, if you don't travel the same time every year or will be traveling all different times, then it becomes less of an issue as some of the trips will fall outside the deadline.
We travel in August since I teach (and will be for at least the next 10 years) so we chose a June UY. Because I am traveling only in month 2 of my UY, if I ever had to cancel that trip or even wanted to downgrade the room type (31 days in advance--less than that and there is a whole different set of rules for points) , I could do so easily without having to worry. I could bank points and if there were borrowed points, it gives me a long time to use them up. But, even when we are retired, our primary travel will be fall or early winter and June UY works well for these travel times as well.
If you travel toward the end of the UY and want to make changes beyond your banking window, it is not that easy, especially if you have borrowed points and have to cancel.
Good luck!