I find this whole thing to be rather silly. Are the pilots crying wolf? Is the FCC ignoring technical issues? The FAA and the FCC are both U.S. Federal agencies. Seems like technical representatives of both agencies could get together in a room or over a video conference to work out the issues.
By some reports, the real problem is that the avionics industry has been building radar altimeters with crappy filtering. It wasn't a problem when they had no neighbors in the radio spectrum. But, now that someone else has moved in next door, there's a problem. And, how close is next door? About 200 MHz. This image is from industry technology group
RTCA:
Note that RTCA issued that report in October 2020.
If that image is correct, who's the bad guy in all of this? If the avionics industry knew this was going to be a problem, did they ignore the FCC's intention to auction the 3700-3980 MHz band? Did the FCC ignore the problem the avionics industry would have filtering out the new 5G band?