Bummer. But my 11” is straight, and all my artist friends who also have the new LTE pros don’t have bending. Why deny yourself what you normally get? I would return the WiFi model, and get the LTE you really want. Open it up in the Apple Store if you must...but it’s a good bet you will get a straight one. I dunno. That’s my advice. Don’t deny yourself LTE if that’s what you always get.
If your fear of the new LTE iPad Pros is too great, then just get an LTE 10.5” Or even the 2018 iPad with LTE. Keep it and then buy the next update to the iPad Pro in 2020 or 2021.
Again, my 11” iPad Pro is straight and I am enjoying it immensely. I say go for it. Return the WiFi model within 13 days and get another LTE version. But that’s me.