Bendgate used to appeared on the iPhone 6 plus, as the aluminum Apple use was not strong enough. At the iPhone 6s, they used a strong version of aluminum, which fixed that.
Now, in 2018, the new iPad pro seems getting the same issue again.
Some user complain online their new iPad pro have a ‘slight bend’ in the aluminum chassis. Supporting Apple’s claims are photos of bent iPad Pro units that exhibit bends at or near the plastic antenna “lines” that trace their way around cellular-capable versions of the device. The company did not specify whether the issue is restricted to LTE models, but users of Wi-Fi only versions have posted complaints regarding similar bending to social media outlets.