When it was announced NIS America was going to localize and publish the title Ys VIII Lacrimosa of Dana for the PS4/PS Vita/PC hours ago, many were confused. XSEED is the publisher that normally localizes games in the Ys series and many are interested in XSEED’s response to the news. It seems that they are okay with it, as Tom (PR Manager of XSEED) gave the following statement on official XSEED Forums.

There’s no need to worry about us: we’re doing just fine. The reason you haven’t heard much from us lately is because we’ve been busy finishing up big projects like Fate/Extella, Story of Seasons: Trio of Towns, Akiba’s Beat, Trails of Cold Steel II, and Trails in the Sky the 3rd, all of which are massive projects that ate up months of time for each of us, and most of which are only just now starting to wind down.
We certainly would’ve loved to work on Ys 8 ourselves, but Falcom made a business decision to work with NISA on it, which we respect. We wish our friends at NIS America much success with this release, and I’ll tell you right now, I’ll certainly be preordering a copy. 😉
-Tom

It’s clear that they were just busy with a number of projects currently and are working hard to get those finished before working on other localization’s, so it is understandable they weren’t able to work on Ys 8 this time out. Even though this doesn’t help people cope with fears of the localized script not matching up with prior Ys releases, I’m positive NIS America will release an example of current localization work to ease fan’s concerns in the future.
Source: XSEED Forum Post