I had seen this coming..
MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
This needed computer hardware upgrade might be related to the risks of having a DAL C architecture instead of a DAL A architecture. (And the difference in failure rate)
With the DAL C architecture the pilot have to perform the fault isolation (since the failure rate is to high), and if that are not reacting fast enough they need to be able mussel the aircraft back in control from a full run-away within the envelope.
This is needed to fulfill CS 25.671.
A DAL A architecture can in principle remove the need for trim wheel and cutout switches (if they want to go this route)