A bug was reported (and marked as confirmed/planning to address) on the official forum where Altana's Favor, Cait Sith's ultimate ability, only grants Reraise I despite the description saying it grants Reraise III. Players who are KO'd have Arise cast on them instead and they will recieve Reraise III upon revival as Arise normally would.
So the question I was going to ask while writing this was if it's a text error or a bug in functionality. However, because Arise grants reraise III (and itself restores the same 90% EXP/EP), I suspect it's a bug in functionality regarding the reraise granted to players who were not KO'd at the time Altana's Favor was used.