One of the reasons the deal was opposed was because many were afraid that AT&T may soon hold a monopoly (or a duopoly with Verizon). Sprint has voiced this out before claiming that should this deal go through, Sprint will need to put themselves up for sale if they were to survive. By divesting some of T-Mobile’s assets, AT&T is hoping to prove that they aren’t looking for a monopoly, although exactly how much of these assets will be divested remain unknown for now.
Leap Wireless owns the Cricket brand and holds about 7 million worth of subscribers. It seems that even with assets being sold to them, it would be hard to match the 100 million plus subscribers that AT&T and Verizon currently hold combined which ultimately makes AT&T’s efforts seem meaningless. It remains to be seen if AT&T will succeed this time round.