My 2nd Generation 12.9 iPad Pro is not an M4. Why can't I update to iPadOS 18?

Has Apple stopped all updates to 18? My iPhone is running iOS 18. I understand there is a bug that affects iPads with an M4 CPU, but I'm pretty sure that mine has an older CPU. I looked up the model number (MP632LL/A), and it says the chip is an A9X chip with 64‑bit architecture and an Embedded M9 coprocessor. It's much easier to find the CPU on a Mac. On another site, I found the CPU shown as Hexa-core 2.38 GHz (3x Hurricane & 3x Zephyr). In any case, it does not have an M4. I think the model number is actually A1670.

OK, I found a wikipedia entry that says

"Both the iPad Pro 2nd Generation 12.9 and iPad Pro 10.5 supported 8 versions of iOS/iPadOS. These included iOS 10, iOS 11, iOS 12, iPadOS 13, iPadOS 14, iPadOS 15, iPadOS 16, and iPadOS 17. At WWDC 2024, it was announced that it would not support iPadOS 18 despite having superior hardware to some models supporting the new update." If that is true, that would explain why I can't update it to 18.