There is this specific situation where you do know that a project should start but there is not yet a clear assignment. This could cause the startup to stagnate. If there is not a clear assignment the project cannot start. But if the project does not start a clear assignment will not be established. This is probably caused by a misunderstanding about project management.
Project management is introduced where normal processes and procedures cannot handle the request due to the lack of control and management to meet the complexity of that request. In fact the request is very different from a normal requests that can be handled by the process. So in that case one cannot say that the request does not meet the entry criteria for the process, as this is the reason to give extra (project) management attention to the request.
One of the first steps in this ambiguous situation is for the Executive to find and talk to the Project Manager. They will discuss that the scope for the project is not yet clear and who is to be involved to make it clear. This means that specialists are asked to identify the Project Deliverable. I would like to call this the 'picture of the future' as it shows (only) what is available by the end of the project, not (yet) what needs to be done for that nor how it is done. Spend appropriate time to 'take this picture'.