do you want to wait for them to license rescue Hayate n such
Yeah because Bandai's dead and their license to that series has expired.
Index and Nagi Sanzenin may be in Shakugan no Shana-tan specials but that dose not mean Funi wants to try and track down the VAs just too dub index
They are (Shakugan no Shana-tan Revenge), and if Funimation gets the remaining Shakugan no Shana-tan specials and dubs them, an alternative (but extremely complicated method) would involve dubbing Index and Nagi Sanzenin (if Funimation rescues Hayate) in-house (if Sentai rescues Hayate and dubs it, then Nagi would be dubbed at Seraphim Digital) and splice those tracks with the rest of the track (Ocean-dubbed). So it's best, for consistency, to have Index, Railgun, and Hayate (in Funimation rescues it) dubbed at Ocean.