It’s a Halion library so it will continue to work for the foreseeable future.
Looks like it was removed from the store after January 1st, about 5 years after it was released. That probably means that the contract expired and wasn’t renewed.
If you’d like to see an updated Halion version of Neo Soul Keys, maybe consider contacting Jamal at GospelMusicians. Halion’s library creation system is far more open now, and you can load libraries for free if you download Halion Sonic SE 3. Perhaps he’ll be interested.