It wasn't permanent even from the initial launch. It was rolling. Once you hit 500 points in 2014, you were Ace through the rest of that year plus the following calendar year. Here's the exact text from the launch email:
From Sephora's VIB terms and conditions:
If Birchbox makes it end with every calendar year and reset on January 1st every year, that's actually not how Sephora does it.
ETA: I just dug this out of the Birchbox Ace T&Cs currently posted on the site:
So there must just be a glitch because the rules still state it's a rolling qualification.