I wouldn't think the oil would have anything to do with JJ's problem.
My guess would be
1) Bad luck
2) air valve issue( possibly combined w/mis diagnosed control issue)
3) controller issue/electrical problem.
The autoshifts I had I always changed at 250,000 miles with synthetic.
Tough repair. I have to wonder how many electrical components get replaced due to a corroded connector that gets cleaned up during replacement.
Of course, being higher mileage, it may have been the proper repair.
Either way, glad you're up and running.