Make the lookups on AO Participants more consistent

I recently discovered that the AO Participants object has a lookup to the Relationship Person ID, but it’s not functional (but will be soon apparently?). There is also no lookup at all to the Company Person ID, which doesn’t seem to make any sense if we’re going to have one for Relationship Person ID. 

Can someone explain what the plan is here? To make things more confusing, I learned that a field called GS Source ID contains the Company Person GSID, but it’s just a string field, not a lookup.