Doesn’t Project Management stifle creativity?

No - in fact a well managed project will encourage cross functional creativity because that is what is needed in ‘change projects’.
An experienced project manager will know when to tap into this creativity and when to drive the project forward.
It is only when project methodologies become bureaucratic and override common sense that creativity can be stifled.

Good project management enables creativity to be expressed in the real world.
Turns it from an idea to a real outcome.
Every excellent web site has been project managed to creative expression.
In other words, project management is essential for creativity to be expressed.
Even artists need to learn the basics of execution.
Projects that are poorly planned, or constrained by tight timeframes or inadequate budget or managed in a pedestrian or bureaucratic way can kill creativity stone dead.
The best tool for killing creativity is design approval by committee where the committee interferes in the design process....
works every time.

Project Management don't kill creativity , but project managers could do .
Projects nature and estime could also kill creativity.
Creative Project manager could drive creativity to insanity.

I agree with Mohammed Awwad answer, a good project management methodology and a good project manager will only enhance creativity in the project, However, in many cases of project management and due to overwhelming the project team with tasks and bureaucratic procedures may result in demotivating the project team and therefore restricting creativity within the project.

Project Management is for me as Orchestra team and the project manager is the leader of this band and the project manager that reconciles all instrumentalists accurately and skill and may invent a new tone Project Manager increase the strength and creativity of the team therefore considered project management disciplines that can not be dispensed within all areas of life and the process

The project manager does not stifle creativity, but the methodology of unilateral view and work solidly, cruelty and not to take advantage of the view and the experience of others It all leads to stifle creativity.