Like a few others have indicated, this is definitely the guidance/requirements we've gotten back from NetApp. Like you, we're definitely opposed to installing Office components on our MBX servers, so that's a no-go. We're currently in the process of backing out SMBR 8 from our beta environment and we'll regroup in the future if/when this is resolved.
I would encourage you to reach out to your account team and let them know your dissatisfaction with this approach. I've gotten some indications that the TMEs/etc are aware that this isn't flying well with customers, so I'm cautiously optimistic that Kroll and NetApp will come up with a "fix" to get it back the way it was (i.e. SMBR+Outlook on a dedicated server).
Hope that helps,
Chris