I bet changing it from "Riftrunner" to "Beyond Divinity" was a marketing decision, since the word "Divinity" is in there.
The word "Divinity" = would appeal to Divine Divinity fans. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
Even non-fans who heard of Divine Divinity and see there's Beyond Divinity might think off the bat, "I bet it is a follow-up/sequel" to Divine Divinity.