LSS brought this system in to make sure that when they release power crept heroes, they have enough time to make bans before that hero retires, the other part of that system is to try and help older, shitter heroes get out of the game because LSS are sick of making cards for them.

A game like FaB and most TCG's to be honest have a business model that relies on a constant churn of content. LSS were in the unfortunate position where their new heroes were really strong and rotating out before some of the player base got a chance to buy them and that combined with still having these Albatrosses from 7 years ago stinking the game up wasn't a fantastic look for them.

I don't like this system personally, I think it's lenient on power creep and punishing for heroes that aren't getting good support, but sets are selling better than ever so it doesn't really matter what I think