Option 1. Relics are continued. New quests added. New grindy steps added. More of the same.

Relic vet: I've hit Lv 60! Yay! Time to start a grindy quest to upgrade my zodiac to 60!

New guy: yay I hit level 60! Time to do...tomestone weapon!

Option 2. Zodiac ends. Heaven relic begins. New quest added. New grindy steps added.

Relic vet: yay I'm Lv 60! Time to start a grindy quest for a heaven relic Lv 60!

New guy: yay I'm Lv 60! Time to start a grindy quest for a heaven relic Lv 60!

What do old relic vets do with new expansion? The next relic quest for a Lv 60 version. If that quest adds an extra glow to your current relic or rewards a different model new weapon doesn't matter. If you relied on relics as weapons in the past you can do the same in the future. Your asking what relic people will do. The next quest. It's really simple.

The people who will actually be affected are people without relics. If they start a fresh line they have a chance to jump in. If they dont, they have to do a crap load of remedial content before they could even start a Lv 60 weapon. Relic vets are good to go no matter what. It's irrelivant to us. The non relic folks are the guys that should be holding their breath and praying.

Vets aren't starti ng over. No matter what happens we will have to do another grindy step. Unless you aski ng for zodiac to get a free upgrade to 60. But that's a whole different discussion.