It seems plausible for the 24 Man Raid coins at the least. They release 3 24 mans per expansion which is the same as the Beast Tribes added so a secondary tab for those coins seems like a no brainer.

Raids would be a bit tricker since there's 12 per expansion and unless they do something similar to Tombstones were there's a universal token akin to Poetics for outdated raids, it would be much harder to make it work and even then, that causes the problem of just grinding the 1st Raid of a Current Tier to buy the gear from the higher tiers without ever needing to actually do those fights unless they keep the token for each fight different, which isn't any different to what is currently the case other than clearing up space.