Wait, they don't sell the CE digital upgrade anymore? No point in adding to mogstore if this option still exists...

EDIT: Looks like they do. [source]

Collector's Edition Digital Upgrade* (Requires Base Game)

Product Name Price
A Realm Reborn & Heavensward Collector's Edition Upgrade $29.99
A Realm Reborn Collector's Edition Upgrade $19.99
Heavensward Collector's Edition Upgrade $19.99
* Collector's Edition Digital Upgrade
・Customers who purchased the standard edition of A Realm Reborn and Heavensward can receive the in-game items included with the collector's edition via a digital upgrade.