To go over what @John-Paul-RAGE , brought up...
The company responsible for localizing Phantasy Star Online 2's Western release is known as "Lionbridge Technology". According to an interview, they were hired by Microsoft to localize Phantasy Star Online 2 and have also worked with the likes of Bandai Namco, Nexon, NCSoft and WB Games.
If you look at the credits and paid attention a bit to some posts on Twitter, Lionbridge Technologies hired freelancers who do in fact have resumes for various titles including the likes of Nier Automata and one who did in fact have experience fan translating stuff for the classic Phantasy Star series.
And of course, Sega of Japan who have their set of translations for things like terminologies (Campship = Gateship, the NA localizers altered this further to "Gateway Ship"), and names ("Gettemhult", "Melfonseana", etc) which may or may not be used ("Patty" and "Tiea" is their official spelling, but the NA version changes it to "Pati" and "Tia" as their name is SUPPOSED to be a pun on "Patientia").
And of course, SEGA of America does have a supervising credit which would certainly explain similarities to the script intended for the original delayed 2013 release (e.g 2013's "Paradigm Matrix" --> 2020's "Divergence Matrix", as well as the more military-esque approach the original 2013 script took such as "Quarters" and "Hostiles").
And of course, while we are it, we have ESTsoft who are doing the active community management for SEGA of Japan (who run the game's servers and develop content for it) and who provide such services like GMs, Customer Support, Social Media, etc. They have a single Translator mainly for communications between them and SEGA of Japan such as for instance... translating support tickets, communicating fan opinion, etc... ESTsoft does listen and document fan concerns... whether the parties who can actually do anything about it actually do something about it is another story; ESTsoft is very well aware of the translation issues but thats ultimately up to either Sega of Japan or Lionbridge Technologies to fix.
As for how we got into the mess to begin with, thats personally something I can't answer unfortunately. My best guess is that the localizers were dealing with time constraints to have as much of the content localized. There's some minor indications that rather than localize up to the content that would actually be made available at launch, the localizers had in fact localized up to Episode 6...