Jumping ahead a bit,
The IET's "6G for Policy Makers" states
"The traditional approach to a next generation mobile technology – seeking ever higher data speed in ever higher spectrum bands – is no longer sustainable. A new approach to mobile generation change is needed in which 6G breaks out of this unsustainable business model."
and a "... need to drive far more effective use of bands below 6GHz that are particularly suitable for wide area coverage ...".
So as well as solving the EMC issues with 5G, SOMEBODY (?) in aviation needs to get involved in the processes that are currently starting to define what 6G is.
[Increasingly unsure much of 5G is legal on the basis of the EMC issues.]