It was not delayed for the audio, at least not for the japanese one. I guess the delay is because of the english dub.
They will add the japanese audio as a gift for the delay.
But it's pretty dumb, because with DLCs, every game should have an option to use the original voices in games, it's not a matter of disk space anymore.
I don't really see the need for that in the first place. The English dub of Persona 4 Golden was pretty good.
It's not the fact the english dub is bad or not, but for example it's completely useless to people which english is not their native language like South America or several European countries.
If they have to play with foreign voices, as japanese and english are both foreign voices for them, they mostly always prefer to have the original voices.
And even for native english speakers, some will always prefer to play with the original voices.
Actually, it's been shown that people think foreign VA is better than their own language because they can't comprehend the flaws in the language, so their mind considers it "perfect"
For example, many Japanese folk think the English VA is better, and that's because they can actually make out the deficiencies in their own language.
Just an interesting tidbit. Play in whatever language you want ^-^
Most japanese doesn't understand english at all, so yeah, it's probably why they might like english voices (like most western people like japanese voices, but most of them doesn't understand the language at all). But there are probably like some of them, they prefer to see things in their original language (so american movies in english).
The problem is most of the times, games doesn't offer the choice because like you said, it's always better to play in wathever language we want.
Like I said upper, with the ability to put voices as DLCs, every game should offer the original voices, whatever language is the original voices (japanese, english, russian, etc...)