The 777X is having a substantial re-engineering of the cabin walls and insulation to reduce their thickness (this on an aircraft already well known for being the noisiest in cruise). Airlines seem happy now with 10-across, so the only reason they can be doing this, which apparently gives another 6" cabin width, is to shave another inch of all the seats again, as well, and go for 3-5-3 11-across.
The 777 was designed for 9 abreast, provisioned for 10 (similarly the 767 was designed for 7, provisioned for 8 - the difference being very few operators used the 8 abreast).
The 777X is not being provisioned for 11 abreast so there is little chance that will happen, but 10 will be more comfortable.
I've pondered before just why the 777 is so noisy, especially aft of the wing. Engine noise or air conditioning ? Are the engines set further inboard than the A330 ? If it's lesser insulation, moves on the 777X to reduce this further are lamentable.
It's mainly ECS - I've even heard Boeing test pilots comment on how much quieter the Airbus ECS is compared to Boeing and wondered how they did it.
Hopefully the ECS noise is being addressed on the 777X.