if its their usual thing, you will not have an account that will use playstation and xbox, your account will be one or the other. so if you have arr-ew on playstation, playing dawntrail on xbox would be an entirely different account. so beware of that. (for instance.. steam and pc are two.. different accounts.. go figure) from a read it looks like xbox may be the same, and xbox users will have a 'coins only' options, likely a microsoft thing.

for me, since it does say you can "link accounts" I would let other people experiment with that first, since you cannot unlink them