Why would the government ever force carriers to accept uncertified devices? So they can emit interference on cellular frequency bands? So they can violate SAR limits and burn people?
The devices would still be subject to FCC certification just like your WiFi chipsets are.
Beyond that, the people developing chipsets generally have better tests for compliance than the carriers, themselves. You should be able to drop one of those chipsets in your phone, plug in a SIM, and get on with life. However, the carriers make you spend a couple of megabucks of bribes and then they will deign to allow your phone on their oh-so-fragile network.
