As far as I know, it is still the case, but now I am curious if something has changed. As of a few weeks ago when I last cancelled a points-booked trip, it was still the case. Also, when you cancel a flight booked with points you can actually select to have the few $ you pay in fees to be refunded. I always just ask for a refund of the fees so that I am not left with a very small travel fund credit.
ETA: According to the T&C, it looks like points do not have particular expiration dates as long as you earn points within a 24-month period, so I stand corrected that spending points does not count as activity.
"Points dont expire as long as you have flight or Partner earning activity every 24 months."
Where are you seeing the expiration date for your points? I would like to check my own account to see if I have anything similar since I just cancelled a points-booked flight last month.