Several complaints popped up online about iPad Pros being shipped with a bent chassis. Apple said this is happening due to manufacturing process but calmed down people, saying it should not worsen over time and will not affect performance and usability over time. This effectively means that if you received a bent iPad Pro, you’re not getting it replaced.

Apple says the weird flex is ok

The weird issue is a result of a cooling process, involving metal and plastic components during manufacturing. It seems like it is more pronounced with the LTE model, even if some Wi-Fi Only users…

Source: GSMArena