Sid --
It seems to me that if there is a leak or failure anywhere in the flexible transfer hose, the fuel will end up being circulated within the main tank and perhaps not be able to top up the supply tanks fast enough to prevent them emptying.
I'd bet that's the sort of defect they would have been looking for in any case would have been found by now, with a directive to check/repair all a/c in service. The only directive we are aware of is a fuel indication issue - i.e. an instrumentation issue, not a safety issue per se.