Apparently there was a reddit leak a few months ago and so far 3 of the 6 character leaks are correct... being Vayne, Locke and Rinoa, if we're to believe this leak as legit the next 3 character for this season will be Yuna, Snow Villiers(Lightning Returns) and one of the villains from XI.
Yuna - depending on which version it is I might be interested, if its shy, timid Yuna from X than I sleep but if its fun X-2 Yuna then I might be interested (also X-2 Yuna brings in future potential for Leblanc or Paine)
Snow Villiers - THIS is a weird pick for a few reasons, 1. Snow isn't a villain not even in LR, 2. LR is a weird game to pick in general for XIII's villain and 3. Caius is just a way better pick in general.
XI villain - I literally have zero opinion on him just like Vayne