All of the following assumes you did not borrow any of those 52 points. If you did, you can't put the points back and they would be "use or lose" if you have to cancel.
The only case where you would definitely lose points would be if they simply didn't show up on their scheduled arrival date. If that happens, all points are forfeited.
There are two dates you need to be concerned with. The most important date is 31 days from their scheduled arrival. If you cancel before that, you will not lose any points. If you cancel inside 31 days, the points go into holding account and cannot be banked. Holding account means restricted booking dates (60 days prior to arrival), and could result in lost points if you can't get availability.
The other critical date is your banking deadline. With a March UY, your banking deadline under the new rules would be the last day of October. If you cancel prior to 31 days out, and it's prior to the last day of October, you can bank with no penalties of any kind.