SFO_FT, what your saying seems to be correct. On Dec 17 I won 250 points on the advent calendar. I just checked my points balance and what was due to expire next April 2021 has now moved to Dec 17, 2021. Happy to see this as I have been booked at one of the Fairmonts in Vancouver for one night in Jan 2021 to keep my points valid. I won't have to spend the $200.00 now for that booking. Thanks for your post.
I also received 2 times 250 points. Also my account shows valid till 17th of dec 2021. So by winning points with the advent calender your points will be extened to date XXXX