I sent a message to YS NET regarding the return of the original English voice actors and received the following reply:
"As for the voice acting, we have received many requests for the original cast to return and understand how important their connection is to the Shenmue community - however, the voice actors are undetermined at this time. Once casting is final, we will let you know through the updates!
Best regards,
M. Toyoshima &
The Shenmue 3 Kickstarter Team"
It seems like they are well aware of the importance of their return. We might just get the English dub we're looking for after all!