And it is still NOT clear if only one continuous run generator/power system/ground power connection for that time would trip ALL off line.
No, it is perfectly clear.
Each GCU is independent. The counter is internal to each GCU. Failure of one GCU only affects that particular GCU, and will not affect any others.
The danger is if all four GCUs were powered up at the same time, then all four would fail at the same time.
This is all clearly discussed in the original FAA AD under the "Supplementary Information" section:
https://s3.amazonaws.com/public-insp...2015-10066.pdf
Also the APUs are not affected (different make/model).