The right question:
Will 7G be needed?
I say no for the next 15 years. Because there are 1425235 other things that are way much important than this.
The paper lists the "earliest plausible" deployment of 7G as 2039-40, so only 1-2 years off your estimate...
It may not be needed, but it will certainly be rolled out.
Right and society only works on one thing at a time