If you change all branches to return 201 (which would be great), keep in mind that you'll probably have to update the test cases (many check for 200s, I assume they do that for POSTs as well as GETs).

Also, people who have written test cases for their apps might expect 200s will get 201s.  This is pretty minor since the test case should fail with a simple message saying 200!=201 and we can warn them to expect this and that it is not a problem.  After all, it isn't returning 30x, 40x, or 50x.  So it is still a valid response.