The Sierra Wireless MC7430 seems to be the only one in the list to be cat6 (300Mbps), but it needs hardware modifications (isolates pins).
And it is also expensive for a cat6 modem, I prefer to wait the support of the EM7565 (600Mbps) that isn't a lot more expensive, but I don't know if the support is planned in a near future.
Not sure how many operators that will actually upgrade till Cat-12. 5G r15 will be release in April and initial test starts sometime this summer nearby where I live.
I guess many MNOs will upgrade as high as possible, many features are SW only. The main problem with reaching high Cat in tge network is lack of available spectrum ... not many MNOs can dedicate more than 50-60MHz of band width to LTE ... which translates to something about 600Mbps in DL. Anything more involves investments in infrastructure (e.g. beam-forming antennae or additional antennae and TRXes for MIMO4x4).