Thanks for referencing the Wiki…
To be clear, that particular bug is extremely specific, though it originally seemed to be extremely common. My guess is that it only occurs when the data for a schedule is perhaps partially corrupted or something like that.
As far as I know, it has not been fixed. I don’t have a Support Ticket open, but Tyler acknowledged this particular bug and said it was pretty complex but critical.
Consensus out here seems to be that there is some overall improvement in schedule reliability, but that may be a side effect of the database tuning, and not specific improvements to the scheduling sub-system.