This is so stupid, and a testament to SWTOR's awful UI team. In any other major title, this sort of thing would not happen. How are unclaimed items attached to specific characters? how is it not account wide? There is no warning that purchasing the item will immediately link the item with the character you're on before you even claim it from the cash shop.
Honestly, I came back to SWTOR to relive the story one last time before it gets shut down (inevitable). Nostalgia trumped annoyance at BW's design "choices" and yet not even 10 minutes in the game I'm smacked in the face with a reminder of just how awful certain elements of the game are. I'm a producer, and I'd be mortified if this sort of thing was not only intentional, but passed QA under my supervision.
You'd think with the cash shop that they'd at least design it to a standard held by nearly every competitor.