So they’re still following the money. Bit of a meta-joke, there.
There’s no further unlocking required; as long as you’re subscribed by April 3rd, you’ll receive both companions. Both companions have been offered before as bonus companions to players who have been subscribed at certain intervals, so it’s possible you might already have these two figures tagging along behind you. But at least you’ll get a spare in case something happens to the original, right? (You will not get a spare. That’s not how companions work.)
Source: Official Site