Is there any evidence this is the case? This sort of thing is a lot like property zoning. If a steel mill starts up next door to your residential property in what used to be a park then there is nothing stopping you from adding more sound proofing to your walls to make it so you can sleep. But should you have to do this and can you do this at all? In this case the neighbouring band was originally used for satellite downlinks. So barely detectable signals with large dishes required. Radar altimeters in aircraft actually used to cause interference to the satellite downlinks when the aircraft flew over.
The fact is that you need to have sufficient physical separation between services in adjacent bands. In this case, you can't expect things to work if an aircraft flies directly over a 4 GHz 5G transmitter at a low altitude. This aspect of adjacent band interference is an important part of spectrum management. You can't just wave the issue away...