I had the same problem today. My 3g disappeared running EP1W debloat. First i tried wiping and flashing GC 2.0 FC, didnt work. I had a full odin of FC GC 1.9 that installed but no 3g. I tried going to 2.0 from that, no dice. I tried ED2, EE4 and EP1Q modems with no success.
Here's what finally fixed it for me.
I downloaded ED1 (
http://www.multiupload.com/JJWSPQHPE7 )
Before i flashed it i REMOVED MY SIM CARD not the sd card but the actual sim (should be white gray or red with verizon 4g on it)
I flashed ED1 via odin and allowed it to boot. once it got to the screen saying i had a SIM error, i powered off and reinstalled the SIM card.
After reboot, my 3g logo was back!
From there, I let it OTA the EE4 update (will take about 10 minutes) rebooted, and then flashed EP1W debloat via ODIN. I have no idea what caused the problem but it is fixed now.
You may be able to cut out a few of the steps but this is what worked for me.