Works both ways though.

I had a relative who visited from Europe on my list. Whom I won't need to upgrade again in the foreseeable future. I can now replace her on my list, still using old credits.

BTW, one thing which is a bit unnice is about the eCredits you get for reaching 100k. If you reach 100k early, these go pop on Feb 29. However people who fly less and reach the cutoff late in the year get to keep them.

Ends up as an incentive not to fly AC and/or credit your miles to a different account and/or to delay all discrertionary traveling when you get close to 100k. Is that really something AC wants to incentive?