They are on a rotation now. So, still unique to Seasons in general and reasonably rare. Just only available roughly once every couple of years.
To ensure those who have already acquired these items still have something to chase, we’ve been adding rewards at the final tier of the Season Journey that are completely new. We figure it’s the best of both worlds this way; people who missed really cool cosmetics the first time around can go back and earn them, and people who have them still have something else to work toward.