I find it strange than a possible 1 second different could cause so much issues.
It's not the time difference that causes problems per se, it's time going backwards. You presumably missed the fact that many Java servers crashed over the last leap second because of a kernel bug that screwed up their internal timers?
We had problems last time due to faults reported by external hardware when it saw the time jump backwards. I'll be at my desk when it happens this time to deal with any problems that come up this time.
And, given the chaos every leap second causes, hopefully we can finally convince the 'experts' to stop fiddling with time.