Deduction time.
John Hardin insisted 2015 right up until TGS last year. Assuming that was doable, which it must have been had Japan not delayed it, dubbing and the rest of the process would take a couple months, three at most.
Extrapolating from that, Persona 5 therefore should come out in July in the West (America only of course). June in Japan. It's not wishful thinking - it's truth.
2017 Europe
Eh...if the Voice Director of Persona games has a habit of posting those phrases when voice recordings begin, and she similarly did it before with PDAN beginning in March and the game releasing in September, doesn't that mean, at the absolute hopeful minimum Persona 5 would have an NA release date of late September? And that's from an un-informed, viewpoint from me, who has no idea how any of this works.
Persona 5 also probably has a lot more dialogue in general than P4DAN did, and this is only extrapolating if they handle voice dubbing as the last step of the localization process. Depending on how it works, it'd be more solid to guess October or maybe even November.
One good thing about this news though, which makes me somewhat optimistic, is the note that they're starting English voice dubbing at all. In a roundabout way, that would mean they have the script, or almost all of the script, which means the the Japan side's most likely completely finished with it.(The script, I mean). So, that at least bodes well for them releasing it in Japan this Summer.
Right now I'll firmly believe in July/Japan and Late September/NA.
I'll also bet on E3 having a dubbed trailer of PV#3 playing with the actual NA release date at the end!
(...Let's pull out the dunce caps again.
)