I'm not disputing that Line2 was originally wifi only. That's not relevant though, since Apple didn't complain about Google Voice using the 3g network to initiate calls in its FCC statement. From the TC article linked above:
"When [you get a] call, the service can either relay the call to your ‘real’ number (the AT&T number assigned to your iPhone), or it can send it to voicemail, depending on the way you’ve set up your call filters."
This is exactly what Google Voice does, and Line2 even included a similar "visual voicemail" feature from the start. It also duplicated the iPhone's dialer pixel for pixel. In Apple's FCC statement the stated reasons for Google Voice's rejection were re-routing of voicemail, duplication of "visual voicemail," and duplication of the iPhone's native dialing functionality.
Is there a claim in the FCC statement against the Google Voice app that doesn't also apply to Line2's app?
And Google didn't address the flaws, because there were no flaws to address! As the acceptance of the Line2 app makes clear, all of Apple's stated complaints about GV weren't real, so why try to get around them when the app will just be rejected for some other completely ridiculous reason?