The email I got today said this (below). I will probably use up my miles in 2020, but maybe not all. Am I right in thinking I can book up to March, 2021 for a flight leaving anytime between then and March 2022?
As of April 1, 2021
based on the ticketing date
The new program will be introduced and implemented as of April 1, 2020.
However, after a 12-month grace period, the changes in mileage redemption
will be enforced as of April 1, 2021.