I would hesitate to agree with that. Sure, we want a clean port opening. Ideally it would just be a clean hole, no burrs, no displacement.
How can a manufacturer prevent a burr or displacement in that location before it ends up with the user? They could chamfer the opening during their process.
Many do not care if something like a burr exists, they say they can shoot it out and wear it smooth. That solution may work with some, but not with all. Many combinations may take an excess in rounds to do that, some may never do it. A 20" chrome lined barrel can be an example all the way to a carbine gas 300 Blackout shooting subs only in a nitrided barrel.