Project Management Baby

Project Management Baby
Recently I come accross a PM that was insisting we giving exact number of the size of the up-coming app. Not a range, not an estimation but an exact size like 20MB. Person also made it very clear if app will be 21MB than we MUST make sure it will be 20BM
What clinet's PM needs to give us:
APIs ready? : NO ( 3rd party invloved)
Design is ready: NO
Wireframes: Kind of yes
Any timline on which we can follow up?: NO

What's wrong with people?