@Johnny so unless I am misunderstanding, you were on Jellybean, then magically fastbooted to Gingerbread, and then OTAed (assuming via the OTA being pushed, not via flashing) to JB ?
Funny thing, if you flash GB or ICS on a JB kernel, it doesn't work, and won't boot, and you end up softbricked.
I was originally on GB and tried to flash directly to a 4.2.2 rom. With no luck matt's JB utility was more readily avail than the GB and ICS on. I tried options 1 and 2 numerous times all resulting in the glitchy screen issue. The screen would be fine if I was scrolling but as soon as I stopped it would show a nice colorful design on the lower third, along with being patchy and slow. I found matt's how to for RSD lite after I ran into a low batt issue partial flash. Altered a usb to make a factory cable. I proceeded to download a 2.3.5 fastboot file put the phone in fastboot and flashed with RSD.
From what I read JB is more of an upgrade to ICS opposed to the 'stand alone' if you will of ICS? Correct me if I am wrong here? I am not sure if I had a kernel issue(didn't update) as I didn't check, but I did have issues booting and black screen issues. Sometimes it took multiple tries to boot up. Otherwise it would go to the back lit black screen after the moto logo. The black screen also persisted after boot up, as it would turn black mid use or would be black returning from an 'off' screen.
I got my GB fastboot from:
Droid-Developers SBF
I believe rsd install was included w matts utility download.
Just install rsd lite and make sure you have the most recent moto drivers.
Then follow matt's rsd how to.
Edit:
To answer you on the push, yes on push. I went to about phone, check for updates.