“The Reward Cache holds all kinds of cool rewards – past season items like the Vault has held, new items you’ve never seen before, transmogs, emotes, dyes, consumables, keys, tokens – all the stuff you want. While new items will be added to the Cache throughout each Season, they won’t rotate out like in the Vault right now. Instead, the items will build up over the course of a few months before all rotating out for the start of a new Season. (You can think of a Season as about 2 Hunt Passes long. Each Escalation cycle was a “Season”).”
There are a few caveats here. First, Phoenix Labs notes that players won’t be able to quickly grind out new rewards; it’ll take longer than it used to, and if you want it to go faster, the company suggests you join the paid Slayers Club, which is basically a temporary subscription that grants several buffs, including double currency. The changeover will happen in April, at which point seasonal vault coins will be “converted into the seasonal currency usable in the next season’s Reward Cache” – and you’ll want to use those before July.
“Joining the Slayers Club is not required to access any part of the game, reach any milestone, or overcome any content,” the studio says. “It’s just a way to get where you’re going a little faster.” Hunt passes and elite hunt passes will also continue to exist.