Hi there!! Many people hatch very successfully in egg cartons. I prefer mine to lay down, but hatching upright can help with eggs that still have excess moisture at hatch time, and some people just prefer it to laying them down. The only big drawback to hatching upright is that if you have a malepositioned it is harder to see and easier to loose them, especially if the egg is tight to the carton.
As to whether a shipped egg needs to be upright at hatch- I don't think there's proven reason that it would make a difference at hatch time unless there is excess moiture. By the time that they are supposed to hatch, or even by the time you go into "lockdown" the air cells should be firm and the chick should be turned and in position for hatching, so I don't see where there is added benefit at that point, just personal preference.
I highly recommend at day 18, candling to check air cells and mark them so that you can get an idea of where the pip should take place and an idea of what kind of air cells you are dealing with, regardless of whether you decide to hatch upright or laying them down.