I suspect there's factors at play here related to optics & perceptions of the team actually conducting a proper "GM search".
Seems crystal clear that Treliving is their guy, which would be a mistake IMO - however, they have to give off the impression that they are doing their due diligence by going through the proper process. It's about finding that right balance between naming someone quickly so they can get to work, versus not appearing to be completely caught off guard & making a knee-jerk hire.
I'd be very surprised if Treliving isn't the team's GM by this time next week.