Oh pls, we did 54 tracks for strings/horns for KH2.5 and that had a budget for a remaster, not a mainline title. Also for Lightning Returns, we just so happen to be able to do things really efficiently. (And to be honest, Shota and I put a lot of work into the project beyond what was expected)
I don't think revamping everything that exists in ARR and then sticking with that route for expansions down the road is unfeasible from a purely resource and workload-oriented view. However, those calls are for people within Square Enix to make, obviously.
FWIW
Shota Nakama did re-orchestrate a few pieces for the FFXIV launch event in China, which was performed live. Met up with Soken, discovered they have a lot of common interests.
BELIEVE