I too have noticed this and fallen foul of cards being taken away just before the end of the season. It sucks.
I also rent cards - I had a rush on a lot of the small value rent ones over the last 36 hours. Some of those are now being rented out by others at 20 to 30 times what I am renting out at, but I am not going to just "recall" the cards to try and get a better rate. Hopefully the small value rental cards (e.g. 0.1 DEC per day) will encourage smaller players to keep on playing and therefore be engaged long term.