This is okay. I think it gives up too much of their choices matter ground to the wailing rabble. If I were designing the system, I would leave in some of the changes hurt.
You start with a full catalog of level1 soulbinds.
Changing out a soulbind causes it to lose 1 level.
Changing out a soulbind incurs a 1 hour cooldown (to limit mid-raid swaps).
Damage/Survivability/Utility upgrade coins are dropped in lots of content (and expensive craftable).
Leveling quests drop uncommon souldbind upgrade coins (upgrades up to lvl 8)
WorldQuest/Dungeons/BGs/LGR drop rare soulbind upgrade coins (upgrades up to lvl 15)
Heroic/Mythic/M+/RatedArena drop epic soulbind upgrade coins (upgrades to level 20+)
This makes it so that the upgrade coins are universally useful and worth keeping around. There is a treadmill to enforce the choice.