No. Amazon considers them a threat. Amazon itself is the largest of large sellers. Any profits made by an upstart large seller are profits that Amazon would rather be making itself.
However as any gigantic organization, Amazon is not a single minded entity. It's likely these activites are handled by totally separate entities with different employees and targets. So it's entirely possible that Amazon is pushing simultaneously for more marketplace and for more own selling actively sabotaging both aspects.
Amazon has all the data anyone would ever need to determine which products the above is true or false for. They would be negligent if they weren't putting that information to use.