I don't think you can really call voices a broken tradition, they weren't used in previous games because of the platform almost certainly, the lack of technology etc for them on a PSone or certainly SNES game.

And anyway I think voices is a good addition and definately they should have done it now they had advanced technology of the Playstation 2 for FFX. For me it made battles more interesting and everything more realistic and I just generally enjoyed the voices.

It wasn't really a "tradition" to not have voices, I think the technology just stopped them.

Anyway it's good to break traditions sometimes, to me it made the game different, new and refreshing.