Just because you can't think of a reason, doesn't mean there isn't a very good reason. The realities of building, selling and financing something of this magnitude are complex and not typically publicized. It's disingenuous for you to push the narrative that Great Gulf has been sitting on their hands since they bought the project when they very recently submitted Official Plan and Zoning Bylaw amendments, which were thoroughly discussed in this very thread. Clearly the design they bought off Mirvish was not "finished", and the re-submission is evidence of that. Furthermore, Gehry's involvement is arguably the most marketable feature about this project. The notion that they would drop him from the project is mere alarmism. Great Gulf is a legitimate builder and they didn't buy this project not to build it. Be patient.