Do we keep both retainers in ARR?

[Inaaca]

Though because all our items are moving to a temp. retainer I think you could fire em (in ARR) and pick new ones before putting the items back into their inventory :P

Not all your items are moving to a temporary npc. Just the excess ones that your inventory can't hold due to your inventory space getting halved. Items in your retainers aren't going to be moved.