its motorola theyve sent the updates to the beta team (aka, motorola feedback network). once motorola feels the updates good, it pushes it out to the devices on the RETUS software channel (all of the USA models), so its not necessarily up to the carrier to provide yall the updates, cause you can get it even if there is no sim card in the phone. its just not quite ready for public release
After dealing with Moto when it came to updates for my Atrix 4G (scrapped 4.0 update) and Atrix HD (ignored in favor of Razr HD), and then moving away to my J5, i wasn't sure how Moto was running things today. From what you're saying, the update process hasn't changed.
It makes sense what you say, b/c I was able to track down the modern day sbf files for flashing via rsd (script used today was seen back then when presented in a non-sbf format, still flashable via rsd), ended up reading android version 9, with build dates back in feb and march of this year.
I'm not following this closely, just poking around for any news for a family member, but we definitely know that its in MFN testing?